Adipogenic and Lipolytic Effects of Ascorbic Acid in Ovariectomized Rats

PURPOSE: Ascorbic acid has been reported to have an adipogenic effect on 3T3-L1 preadipocytes, while evidence also suggests that ascorbic acid reduces body weight in humans. In this study, we tested the effects of ascorbic acid on adipogenesis and the balance of lipid accumulation in ovariectomized rats, in addition to long-term culture of differentiated 3T3-L1 adipocytes. MATERIALS AND METHODS: Murine 3T3-L1 fibroblasts and ovariectomized rats were treated with ascorbic acid at various time points. In vitro adipogenesis was analyzed by Oil Red O staining, and in vivo body fat was measured by a body composition analyzer using nuclear magnetic resonance. RESULTS: When ascorbic acid was applied during an early time point in 3T3-L1 preadipocyte differentiation and after bilateral ovariectomy (OVX) in rats, adipogenesis and fat mass gain significantly increased, respectively. However, lipid accumulation in well-differentiated 3T3-L1 adipocytes showed a significant reduction when ascorbic acid was applied after differentiation (10 days after induction). Also, oral ascorbic acid administration 4 weeks after OVX in rats significantly reduced both body weight and subcutaneous fat layer. In comparison to the results of ascorbic acid, which is a well-known cofactor for an enzyme of collagen synthesis, and the antioxidant ramalin, a potent antioxidant but not a cofactor, showed only a lipolytic effect in well-differentiated 3T3-L1 adipocytes, not an adipogenic effect. CONCLUSION: Taking these results into account, we concluded that ascorbic acid has both an adipogenic effect as a cofactor of an enzymatic process and a lipolytic effect as an antioxidant.

Alteração do tecido conjuntivo orbitário após aplicação de bimatoprost: estudo experimental em ratos / Changes of orbital connective tissue after bimatoprost injection. Experimental study in rats

RESUMO O bimatoprost é utilizado comumente como a droga de primeira escolha no tratamento do glaucoma primário de ângulo aberto. Hiperemia conjuntival, crescimento dos cílios, enoftalmia, escurecimento cutâneo periocular, sulco palpebral profundo e prurido ocular têm sido relatados em pacientes que receberam bimatoprost em doses únicas diárias durante cerca de 3 meses. O mecanismo exato para estes efeitos adversos permanece desconhecido. Objetivo: Verificar em animais de experimentação, as alterações do tecido conjuntivo orbitário após injeção retrobulbar de bimatoprost 0,03%. Métodos Foram utilizados trinta e seis ratos machos (Rattus norvegicus albinus) submetidos a diferentes períodos de injeção retrobulbar de bimatoprost à direita. O material exenterado foi submetido à análise histológica, morfométrica (diâmetro, densidade numérica e densidade de volume dos adipócitos) e imunohistoquímica para marcação do VEGF. Os resultados destas análises foram submetidos à análise descritiva com o auxílio do software R. O nível de significância adotado foi 5%. Para as comparações foi proposto o modelo de regressão linear com efeitos mistos. Resultados: Na amostra estudada, as órbitas submetidas a injeções retrobulbares de bimatoprost apresentaram ao redor do nervo óptico tecido conjuntivo mais espesso, com inúmeros capilares e vasos de vários calibres e a redução da quantidade, diâmetro e volume das células adiposas estatisticamente significativo quando comparado à órbita contralateral e ao grupo controle. Conclusão: Neste estudo observaram-se as seguintes alterações potencialmente reversíveis do tecido conjuntivo orbitário nos ratos submetidos à injeção retrobulbar de bimatoprost: 1) redução da quantidade, do diâmetro e do volume das células adiposas orbitárias; 2) neovascularização local; 3) espessamento e remodelamento das fibras de colágeno na cavidade orbitária.

ABSTRACT Bimatoprost is commonly used as the drug of first choice in the treatment of primary open-angle glaucoma. Conjunctival hyperemia, eyelash growth, enophthalmos, periocular skin pigmentation, deep lid sulcus and itching eyes have been reported in patients that daily received single dosages during a three month period. The exact mechanism for these adverse effects remains unknown. Objective: to verify alterations, in test animals, of the orbital connective tissue after peribulbar injections of bimatoprost 0.03% using histological and immune-histochemical analysis. Methods: thirty six male test rats (Rattus norvegicus albinus) were subjected to various periods of periocular injections of bimatoprost 0.03% in the right eye.All extracted material was submitted to histological, morphometric (diameter, numeric density and density of adipocyte volume) and immune-histochemical analysis to mark the vascular endothelial growth factor (VEGF). These analysis results were then submitted to a descriptive analysis with the help of R software. The significance level used was 5%. For comparison, the model of linear regression with mixed effects was proposed. Results: In the sample studied, the eye sockets that were continuously submitted to bimatoprost had a denser conjunctival tissue around the optic nerve, with numerous capillaries and blood vessels of various sizes and a reduction of quantity, diameter and volume of adipose cells of statistic importance when compared to the contralateral eye socked and the control group. Conclusion: In this study, the following potentially reversible changes of orbital connective tissue were observed in test rats subjected to periocular injection of bimatoprost: 1) reduction of quantity, diameter and volume of orbital adipose cells; 2) local neovascularization; 3) thickening and remodeling of collagen fibers in the orbital cavity.

Potential role of marine algae extract on 3T3-L1 cell proliferation and differentiation: an in vitro approach

BACKGROUND: From ancient times, marine algae have emerged as alternative medicine and foods, contains the rich source of natural products like proteins, vitamins, and secondary metabolites, especially Chlorella vulgaris (C. vulgaris) contains numerous anti-inflammatory, antioxidants and wound healing substances. Type 2 diabetes mellitus is closely associated with adipogenesis and their factors. Hence, we aimed to investigate the chemical constituents and adipo-genic modulatory properties of C. vulgaris in 3T3-L1 pre-adipocytes. RESULTS: We analysed chemical constituents in ethanolic extract of C. vulgaris (EECV) by LC-MS. Results revealed that the EECV contains few triterpenoids and saponin compounds. Further, the effect of EECV on lipid accumulation along with genes and proteins expressions which are associated with adipogenesis and lipogenesis were evaluated using oil red O staining, qPCR and western blot techniques. The data indicated that that EECV treatment increased differentiation and lipid accumulation in 3T3-L1 cells, which indicates positive regulation of adipogenic and lipogenic activity. These increases were associated with up-regulation of PPAR-γ2, C/EBP-α, adiponectin, FAS, and leptin mRNA and protein expressions. Also, EECV treatments increased the concentration of glycerol releases as compared with control cells. Troglitazone is a PPAR-γ agonist that stimulates the PPAR-y2, adiponectin, and GLUT-4 expressions. Similarly, EECV treatments significantly upregulated PPAR-γ, adiponectin, GLUT-4 expressions and glucose utilization. Further, EECV treatment decreased AMPK-α expression as compared with control and metformin treated cells. CONCLUSION: The present research findings confirmed that the EECV effectively modulates the lipid accumulation and differentiation in 3T3-L1 cells through AMPK-α mediated signalling pathway.

Renin-angiotensin system blockers regulate the metabolism of isolated fat cells in vitro

Due to the presence of the renin-angiotensin system (RAS) in tissues and its specific influence on white adipose tissue, fat cells are possible targets of pharmacological RAS blockers commonly used as anti-hypertensive drugs. In the present study, we investigated the effects of different RAS blockers on fat cell metabolism, more specifically on lipolysis, lipogenesis and oxidation of energy substrates. Isolated primary adipocytes were incubated with different RAS blockers (aliskiren, captopril and losartan) in vitro for 24 h and lipolysis, lipogenesis and glucose oxidation capacities were determined in dose-response assays to a β-adrenergic agonist and to insulin. Although no change was found in lipolytic capacity, the RAS blockers modulated lipogenesis and glucose oxidation in a different way. While captopril decreased insulin-stimulated lipogenesis (−19% of maximal response and −60% of insulin responsiveness) due to reduced glucose derived glycerol synthesis (−19% of maximal response and 64% of insulin responsiveness), aliskiren increased insulin-stimulated glucose oxidation (+49% of maximal response and +292% of insulin responsiveness) in fat cells. Our experiments demonstrate that RAS blockers can differentially induce metabolic alterations in adipocyte metabolism, characterized by a reduction in lipogenic responsiveness or an increase in glucose oxidation. The impact of RAS blockers on adipocyte metabolism may have beneficial implications on metabolic disorders during their therapeutic use in hypertensive patients.

Effect of resveratrol on mitochondrial activity in differentiated mature adipocytes / Efecto del resveratrol sobre la actividad mitocondrial en adipocitos maduros diferenciados

Obesity has reached epidemic proportions, the World Health Organization (WHO) estimates that there are more than 1,000 million overweight adults world-wide. Furthermore, obesity is characterized as an overgrowth of white adipose tissue as a result of adipocyte hypertrophy and hyperplasia. Mitochondria is considered the source of energy within the adipocyte, since it contains the molecular machinery, and it is involved in a large number of metabolic pathways, besides the transformation of chemical energy into adenosine triphosphate. Mitochondria shortage and adipocyte dysfunction result in an excessive accumulation of triacylglycerol in the cytoplasm, which determines an imbalance between energy production and energy expenditure. Resveratrol (RSV) is a polyphenol found in different plants and its effects have been associated with mitochondrial biogenesis. An adipogenesis in vitro model (3T3-L1 preadipocytes) was used, and these cells were differentiated into mature adipocytes. Subsequently the effect of RSV on the adipocytes morphology, the lipid content and mitochondrial activity was evaluated using microscopic and flow cytometry techniques. The effect of RSV on differentiated mature adipocytes, was characterized by the decrease in lipid content and the consequently declination of the mitochondrial activity. 3T3-L1 preadipocytes retained the differentiation ability until passage 18. The RSV at doses of 25 and 50 µM for 48 hours in differentiated mature adipocytes promoted the decreased in lipid content probably due to an increase in mitochondrial activity in the early hours of RSV exposure, causing the consequently declination of mitochondrial activity at the end of 48 hours.

La obesidad ha tomado dimensiones epidémicas globales y la Organización Mundial de la Salud estima que hay más de 1,000 millones de adultos con sobrepeso. Así mismo, la obesidad se ha caracterizado como la expansión del tejido adiposo blanco condicionada por la hipertrofia e/o hiperplasia de los adipocitos. La mitocondria es considerada la fuente de energía dentro del adipocito, debido a que contiene la maquinaria molecular que dirige, a través de diversas vías metabólicas, la transformación de la energía química en adenosíntrifosfato. La escasez de mitocondrias así como su disfunción en el adipocito, resulta en una acumulación excesiva de triacilgliceroles en el citoplasma, lo que condiciona un desequilibrio entre producción de energía y gasto energético. El resveratrol (RSV) es un polifenol que se encuentra en diferentes grupos de plantas y sus efectos se han asociado con la inducción de genes para la biogénesis mitocondrial. Se empleó un modelo de adipogénesis (in vitro) materializado por una línea celular de preadipocitos 3T3-L1, mismos que se diferenciaron a adipocitos maduros. Posteriormente se evaluó el efecto del RSV sobre la morfología, contenido lipídico y actividad mitocondrial en los adipocitos maduros diferenciados a través de las técnicas: microscopía invertida, confocal y citometría de flujo. El efecto del RSV sobre los adipocitos maduros diferenciados, se caracterizó por la disminución del contenido lipídico y consecuentemente de la actividad mitocondrial. Los preadipocitos 3T3-L1 conservaron la capacidad de diferenciación hasta el pase 18. Por otra parte, el resveratrol a dosis de 25 y 50 µM durante 48 horas en adipocitos maduros diferenciados, promueve una disminución en el contenido lipídico probablemente debido a un aumento de la actividad mitocondrial en las primeras horas de exposición al tratamiento, provocando la disminución de la actividad mitocondrial al término de 48 horas.

Triiodothyronine modulates the expression of leptin and adiponectin in 3T3-L1 adipocytes / Triiodotironina modula a expressão de leptina e adiponectina em adipócitos 3T3-L1

Objective To study the effect of different doses of triiodothyronine on gene expression of the adipokines leptin and adiponectin, at different times, and to evaluate the difference in expression between the two adipokines in each group. Methods 3T3-L1 adipocytes were incubated with triiodothyronine at physiological dose (10nM) and supraphysiological doses (100nM or 1,000nM), or without triiodothyronine (control, C) for 0.5, 6, or 24 hours. Leptin and adiponectin mRNA was detected using real-time polymerase chain reaction (RT-PCR). One-way analyses of variance, Tukey’s test or Student’s t test, were used to analyze data, and significance level was set at 5%. Results Leptin levels decreased in the 1,000nM-dose group after 0.5 hour. Adiponectin levels dropped in the 10nM-dose group, but increased at the 100nM dose. After 6 hours, both genes were suppressed in all hormone concentrations. After 24 hours, leptin levels increased at 10, 100 and 1,000nM groups as compared to the control group; and adiponectin levels increased only in the 100nM group as compared to the control group. Conclusion These results demonstrated fast actions of triiodothyronine on the leptin and adiponectin expression, starting at 0.5 hour, at a dose of 1,000nM for leptin and 100nM for adiponectin. Triiodothyronine stimulated or inhibited the expression of adipokines in adipocytes at different times and doses which may be useful to assist in the treatment of obesity, assuming that leptin is increased and adiponectin is decreased, in obesity cases. .

Objetivo Examinar o efeito de diferentes doses de triiodotironina sobre a expressão gênica das adipocinas leptina e adiponectina, em diferentes períodos de tempo, além de avaliar a diferença de expressão entre as duas adipocinas em cada grupo. Métodos Adipócitos 3T3-L1 foram incubados com triiodotironina nas doses fisiológica (10nM) e suprafisiológicas (100nM ou 1.000nM), ou na ausência de triiodotironina (controle, C) durante 0,5, 6 ou 24 horas. O mRNA das adipocinas foi analisado em tempo real, utilizando a reação em cadeia de polimerase. Para as análises dos dados, foi utilizada a análise de variância, complementada com o teste de Tukey, ou o teste t de Student com 5% de significância. Resultados Os níveis de leptina diminuíram no grupo com dose de 1.000nM em 0,5 hora. A adiponectina também diminuiu no grupo com dose de 10nM, porém se elevou com a dose de 100nM. Após 6 horas, ambos os genes foram suprimidos em todas concentrações de hormônio. Em 24 horas, os níveis de leptina foram elevados em 10, 100 e 1.000nM, em relação ao grupo controle. No que concerne à adiponectina, observou-se aumento apenas no grupo cuja dose foi de 100nM, em comparação ao controle. Conclusão Foram demonstradas ações rápidas da triiodotironina sobre a expressão da leptina e da adiponectina, iniciando em 0,5 hora na dose de 1.000nM, para a primeira, e na dose de 100nM, para a segunda. A triiodotironina estimulou ou inibiu a expressão de adipocinas em adipócitos em diferentes tempos e doses, o que pode auxiliar no tratamento da obesidade, levando em consideração que, nesta, a leptina está aumentada e adiponectina, diminuída. .

Atividade de novos derivados de tiazolidinodionas sobre a diferenciação de pré-osteoblastos e pré-adipócitos / Activity of new derivatives of thiazolidinediones on differentiation of preosteoblasts and preadipocytes

As tiazolidinodionas (TZDs) são sensibilizadores de insulina utilizados no tratamento do diabetes mellitus tipo 2. Contudo, apesar dos efeitos benéficos sobre a glicemia, importantes efeitos adversos incluindo perda óssea e aumento de adiposidade são relatados com o uso clínico das TZDs. Assim, é necessário o desenvolvimento de novos derivados de TZDs com potenciais efeitos benéficos sobre a hiperglicemia e menos efeitos adversos. Neste estudo, investigamos os efeitos de 5 novos derivados de TZDs (LYSO-7, GQ-89, GQ-150, GQ-177 e SF-3) sobre a diferenciação celular de pré-osteoblastos murinos MC3T3-E1, pré-adipócitos murinos 3T3-L1 e pré-adipócitos SGBS de linhagem humana. Seus potenciais efeitos sobre a utilização de glicose, a produção de adipocinas e mediadores pró-inflamatórios também foram avaliados, utilizando linhagens murinas e humanas de adipócitos, e macrófagos THP-1 de linhagem humana. O principal achado de nosso estudo foi que os novos derivados de TZDs estimulam a utilização celular de glicose, porém não alteram o processo de diferenciação celular de pré-osteoblastos e pré-adipócitos, quando comparados com a TZD clássica Rosiglitazona. Conforme esperado, o tratamento com Rosiglitazona na concentração de 5 µM inibiu a osteogênese de pré-osteoblastos murinos MC3T3-E1. No entanto, o tratamento com 2 novos derivados de TZDs (GQ-89 e GQ-177) na mesma concentração não afetou a diferenciação celular, sendo possível observar níveis de mineralização de matriz extracelular similares aos do grupo controle. Além disso, enquanto a GQ-89 estimulou a atividade da fosfatase alcalina, a GQ-177 não modulou sua atividade enzimática e induziu a expressão gênica de osteocalcina. Contudo, ambos inibiram a expressão de Runx2 e colágeno. Por sua vez, quando os efeitos foram avaliados sobre a diferenciação de adipócitos, foi possível observar que ao contrário do efeito pró-adipogênico constatado com a Rosiglitazona na concentração de 1 µM, as TZDs GQ-150, GQ-177, LYSO-7 e SF-3 foram incapazes de induzir o acúmulo lipídico em pré-adipócitos murinos e humanos. Além disso, a GQ-150 inibiu a expressão gênica de C/EBPα, assim como a expressão gênica e os níveis protéicos de CD36, enquanto que a SF-3 estimulou a expressão gênica de C/EBPα e de FABP4 e diminuiu a expressão gênica e os níveis protéicos de CD36, os quais não foram modificados pela LYSO-7 em pré-adipócitos murinos 3T3-L1. No entanto, em pré-adipócitos SGBS de linhagem humana, nenhum efeito sobre os marcadores de fenótipo adipogênico C/EBPα e FABP4 foi observado com os novos derivados de TZDs. Ademais, os novos derivados de TZDs não interferiram na via de sinalização de Wnt, não apresentaram qualquer efeito sobre a expressão de adipocinas (adiponectina, resistina e leptina) e mediadores pró-inflamatórios (IL-6, CCL2/MCP-1, TNF-α e JNK), bem como não ativaram o fator de transcrição PPARγ no ensaio de gene repórter. Por sua vez, a LYSO-7, GQ-150 e SF-3 aumentaram o consumo de glicose em presença de insulina em adipócitos 3T3-L1 e modificaram a atividade de enzimas mitocondriais em adipócitos SGBS e macrófagos THP-1. Entretanto, o efeito sensibilizador de insulina foi confirmado somente com a GQ-177 pelo aumento da captação de glicose e somente a LYSO-7 e a SF-3 foram capazes de inibir o consumo de oxigênio e modificar a taxa de glicólise em macrófagos, sugerindo que também poderiam alterar os níveis de ATP/ADP. Considerando que baixos níveis de ATP estimulam a via de sinalização de AMPK, essa via também foi investigada em nosso estudo. Entretanto, os resultados sobre a ativação de AMPK foram inconclusivos. Desse modo, nossos resultados apontam que os novos derivados de TZDs não atuam como ligantes de PPARγ, apresentam atividade sensibilizadora de insulina in vitro, e que exercem menores efeitos antiosteoblásticos e adipogênicos quando comparados com a Rosiglitazona. Mais estudos são necessários para elucidar os mecanismos responsáveis por esses efeitos, bem como para estabelecer se os novos derivados de TZDs são mais seguros in vivo, com relação ao risco de fraturas ósseas e ganho de massa adiposa

Thiazolidinediones (TZDs) are insulin sensitizers used in the treatment of type 2 diabetes mellitus. However, despite the beneficial effects on blood glucose, significant adverse effects including bone loss and increased adiposity are reported with the clinical use of TZDs. Thus, it is necessary to develop new derivatives of TZDs with potential beneficial effects on hyperglycemia and fewer adverse effects. In this study, we investigated the effects of 5 new derivatives of TZDs (LYSO-7, GQ-89, GQ-150, GQ-177 e SF-3) on cellular differentiation in murine MC3T3-E1 preosteoblasts, murine 3T3-L1 preadipocytes, and SGBS preadipocytes from human lineage. Potential effects on glucose consumption, adipokines, and pro-inflammatory mediators were also assessed using murine and human strains of adipocytes, and macrophages from human THP-1 lineage. The main finding of this study was that new derivatives of TZDs stimulate glucose consumption, but do not change the cell differentiation process of preosteoblasts and preadipocytes compared to classical TZD Rosiglitazone. As expected, the treatmet with Rosiglitazone, at 5µM, inhibited the osteogenesis in murine MC3T3-E1 preosteoblasts. However, the treatment with 2 new derivatives of TZDs (GQ-89 and GQ-177) at the same concentration did not affect cell differentiation, and levels of mineralization of the extracellular matrix similar to the control group were observed. In addition, whereas the GQ-89 stimulated the activity of alkaline phosphatase, GQ-177 does not modulate its enzymatic activity and induced gene expression of osteocalcin. However, both of them inhibit the expression of Runx2 and collagen. In turn, when the effects were assessed on the adipocyte differentiation, unlike the proadipogenic effect observed with Rosiglitazone at a concentration of 1 µM, the new TZDs GQ-150, GQ-177, LYSO-7 and SF-3 were unable to induce lipid accumulation in human and murine preadipocytes. In addition, GQ-150 inhibited the gene expression of C/EBPα , as well as the gene expression and protein levels of CD36, whereas SF-3 stimulated the gene expression of C/EBPα and FABP4 and decreased gene expression and protein levels of CD36, which was not modified by LYSO-7 on murine 3T3- L1 preadipocytes. However, no effect on markers of adipogenic phenotype C/EBPα and FABP4 has been observed with the novel derivatives of TZDs in human SGBS preadipocytes. Furthermore, the new derivatives of TZDs do not interfere with the Wnt signaling pathway, showed no effect on the adipokines expression (adiponectin, resistin and leptin) and proinflammatory mediators (IL-6, CCL2 / MCP-1, TNF α and JNK) and did not activate the transcription factor PPARγ in the gene reporter assay. In turn, LYSO-7, GQ-150, and SF-3 increased glucose consumption in the presence of insulin in 3T3-L1 adipocytes and modified the activity of mitochondrial enzymes in SGBS adipocytes and THP-1 macrophages. However, the effect on insulin sensitization was confirmed only to GQ-177 that increased glucose uptake and just LYSO-7 and SF-3 were able to inhibit oxygen consumption and modify the rate of glycolysis in macrophages, suggesting that they could also alter the levels of ATP/ADP. Since low levels of ATP could stimulate AMPK pathway, this signaling pathway was also investigated in our study. However, the results on the AMPK activation were inconclusive. Thus, our results demonstrate that the new derivatives of TZDs do not act as PPARγ ligands, present insulin sensitizing activity in vitro, and display minor antiosteoblastic and adipogenic effects when compared to Rosiglitazone. More studies are needed to elucidate the exact mechanisms responsible for these effects, as well as to establish whether the safety of the new TZDs with respect to the risk of bone fractures and body mass gain using in vivo models

BAFF knockout improves systemic inflammation via regulating adipose tissue distribution in high-fat diet-induced obesity

Obesity is recognized as a chronic low-grade inflammatory state due to adipose tissue expansion being accompanied by an increase in the production of proinflammatory adipokines. Our group is the first to report that B-cell-activating factor (BAFF) is produced from adipocytes and functions as a proinflammatory adipokine. Here, we investigated how loss of BAFF influenced diet-induced obesity in mice by challenging BAFF-/- mice with a high-fat diet for 10 weeks. The results demonstrated that weight gain in BAFF-/- mice was >30% than in control mice, with a specific increase in the fat mass of the subcutaneous region rather than the abdominal region. Expression of lipogenic genes was examined by quantitative real-time PCR, and increased lipogenesis was observed in the subcutaneous adipose tissue (SAT), whereas lipogenesis in the epididymal adipose tissue (EAT) was reduced. A significant decrease in EAT mass resulted in the downregulation of inflammatory gene expression in EAT, and more importantly, overall levels of inflammatory cytokines in the circulation were reduced in obese BAFF-/- mice. We also observed that the macrophages recruited in the enlarged SAT were predominantly M2 macrophages. 3T3-L1 adipocytes were cultured with adipose tissue conditioned media (ATCM), demonstrating that EAT ATCM from BAFF-/- mice contains antilipogenic and anti-inflammatory properties. Taken together, BAFF-/- improved systemic inflammation by redistributing adipose tissue into subcutaneous regions. Understanding the mechanisms by which BAFF regulates obesity in a tissue-specific manner would provide therapeutic opportunities to target obesity-related chronic diseases.

Evaluation of palpebral fissure and orbital volume after bimatoprost 0.03% orbital injections. Experimental study in rats / Avaliação da fenda palpebral e do volume orbitário após aplicações orbitárias de bimatoprost 0.03%. Estudo experimental em ratos

Objective: To evaluate in experimental animals the changes of the palpebral fissure and the orbital volume after orbital injection of bimatoprost 0.03%. Methods: Two main groups of Wistar rats were analyzed, one after orbital injection of bimatoprost 0.03% and another, a control group, after orbital injection of saline solution. The calculation of the palpebral fissure was done on images by means of computer processing, using the program Image J. After taking photographs, the animals were submitted to bilateral orbital exenteration and the volume was calculated in all the animals by the water displacement method (Archimedes’ Principle). Results: While comparing the measurements of the palpebral fissure and the orbital volume among animals given an injection with bimatoprost 0.03% and the control group it was found that there were no statistically significant differences. Conclusions: In this study there were no statistically significant differences in the measurement of the vertical palpebral fissure and the orbital volume among animals given the orbital injection of bimatoprost 0.03% and the animals of the control group. .

Objetivo: Avaliar em modelos experimentais as alterações da fenda palpebral e do volume orbitário após aplicação orbitária de bimatoprost 0,03%. Métodos: Dois principais grupos compostos por ratos Wistar foram analisados, sendo comparados os animais submetidos à injeção orbitária de bimatoprost 0.03% com os submetidos à injeção orbitária de solução salina. O cálculo da fenda palpebral vertical foi obtido através de imagem computadorizada utilizando-se o programa Image J. Após serem fotografados os animais foram submetidos à exenteração bilateral e o volume orbitário foi calculado pelo método de deslocamento da coluna de água (Princípio de Archimedes). Resultados: Quando foram comparadas as medidas da fenda palpebral vertical e do volume orbitário entre os animais submetidos a injeção de bimatoprost 0.03% e o grupo controle não foi obsevada diferença estatisticamente significante. Conclusão: Neste estudo não houve diferença estatisticamente significante nas medidas da fenda palpebral vertical e no volume orbitário entre os animais submetidos à injeção orbitária de bimatoprost 0.03% e o grupo controle. .

Short-term effects of triiodothyronine on thyroid hormone receptor alpha by PI3K pathway in adipocytes, 3T3-L1 / Efeitos rápidos da triiodotironina no receptor de hormônio tireoidiano alfa pela via PI3K em adipócitos, 3T3-L1

Objective The present study aimed to examine the effects of thyroid hormone (TH), more precisely triiodothyronine (T3), on the modulation of TH receptor alpha (TRα) mRNA expression and the involvement of the phosphatidyl inositol 3 kinase (PI3K) signaling pathway in adipocytes, 3T3-L1, cell culture. Materials and methods: It was examined the involvement of PI3K pathway in mediating T3 effects by treating 3T3-L1 adipocytes with physiological (P=10nM) or supraphysiological (SI =100 nM) T3 doses during one hour (short time), in the absence or the presence of PI3K inhibitor (LY294002). The absence of any treatment was considered the control group (C). RT-qPCR was used for mRNA expression analyzes. For data analyzes ANOVA complemented with Tukey’s test was used at 5% significance level. Results T3 increased TRα mRNA expression in P (1.91±0.13, p<0.001), SI (2.14±0.44, p<0.001) compared to C group (1±0.08). This increase was completely abrogated by LY294002 in P (0.53±0.03, p<0.001) and SI (0.31±0.03, p<0.001). To examine whether TRα is directly induced by T3, we used the translation inhibitor cycloheximide (CHX). The presence of CHX completely abrogated levels TRα mRNA in P (1.15±0.05, p>0.001) and SI (0.99±0.15, p>0.001), induced by T3. Conclusion These results demonstrate that the activation of the PI3K signaling pathway has a role in T3-mediated indirect TRα gene expression in 3T3-L1 adipocytes. .

Objetivo O objetivo do presente estudo foi analisar os efeitos do hormônio tireoidiano (HT), triiodotironina (T3), na modulação da expressão de mRNA do receptor alfa (TRα) de HT e o envolvimento da via de sinalização da via fosfatidilinositol 3-quinase (PI3K) em adipócitos, 3T3-L1. Materiais e métodos: Foi examinado o envolvimento da via PI3K nos efeitos do T3 nos tratamentos de adipócitos, 3T3-L1, nas doses fisiológica (P=10nM) ou suprafisiológica (SI =100 nM) durante uma hora (tempo curto), na ausência ou na presença do inibidor da PI3K (LY294002). A ausência de qualquer tratamento foi considerada o grupo controle (C). RT-qPCR foi utilizado para analisar a expressão do mRNA. Para as análises dos dados, utilizou-se ANOVA complementada com o teste de Tukey a 5% de significância. Resultados O T3 aumentou a expressão de mRNA de TRα em P (1,91±0,13, p<0,001) e SI (2,14±0,44, p<0,001) em comparação com o grupo C (1±0,08). Esse aumento foi completamente abolido por LY294002 em P (0,53±0,03, p<0,001) e SI (0,31±0,03, p<0,001). Para examinar se a expressão de TRα foi diretamente induzida pelo T3, utilizou-se o inibidor de tradução, ciclohexamida (CHX). A presença de CHX reduziu os níveis de mRNA de TRα em P (1,15±0,05, p>0,001) e SI (0,99±0,15, p>0,001), induzidos pelo T3. Conclusão Esses resultados demonstram que a ativação da via de sinalização de PI3K tem um papel importante na expressão do gene TRα mediada indiretamente pelo T3, em adipócitos 3T3-L1. .

Topical Prostaglandin Analogue Drugs Inhibit Adipocyte Differentiation

PURPOSE: To investigate the effects of topical prostaglandin analogue drugs on the differentiation of adipocytes. METHODS: Differentiation of 3T3-L1 preadipocytes was induced with isobutylmethylxanthine, dexamethasone, and insulin. 3T3-L1 cells were exposed to 0.008, 0.08, 0.2 microM of latanoprost and travoprost. Reverse transcription polymerase chain reaction for mRNA expression of lipoprotein lipase and peroxisome proliferator-activated receptor gamma 2 (PPARgamma2), and glycerol-3-phosphate dehydrogenase (G3PDH) assays were performed to examine the effects on early and late differentiation, respectively. Also, glycerol assays were done to evaluate the effect of prostaglandin analogues on lipolysis after differentiation. RESULTS: Both prostaglandin analogues inhibited differentiation of preadipocytes. Topical prostaglandin analogues significantly decreased G3PDH activity, a marker of late differentiation. However, topical prostaglandin analogues did not change mRNA expressions of lipoprotein lipase and PPARgamma2, markers of early differentiation. The activities of the early markers of differentiation were not changed significantly before and after growth arrest. Compared to latanoprost, travoprost decreased G3PDH activity more significantly (p 0.05). CONCLUSIONS: Prostaglandin analogues display an inhibitory effect on the differentiation of adipocytes when the cells start to differentiate especially in the late stage of differentiation. Thus, commercial topical prostaglandin analogues may decrease the fat contents of eyelids.

Modulation of thyroid hormone receptors, TRα and TRβ, by using different doses of triiodothyronine (T3) at different times / Modulação dos receptores de hormônio tireoidiano, TRα e TRβ, utilizando diferentes doses de triiodotironina (T3) em diferentes tempos

OBJECTIVE: To examine the effect of different doses of triiodothyronine (T3) on mRNA levels of thyroid hormone receptors, TRα and TRβ, at different times. MATERIALS AND METHODS: 3T3-L1 adipocytes were incubated with T3 (physiological dose: F; supraphysiological doses: SI or SII), or without T3 (control, C) for 0.5, 1, 6, or 24h. TRα and TRβ mRNA was detected using real-time polymerase chain reaction. RESULTS: F increased TRβ mRNA levels at 0.5h. After 1h, TRα levels increased with F and SI and TRβ levels decreased with SII compared with C, F, and SI. After 6h, both genes were suppressed at all concentrations. In 24h, TRα and TRβ levels were similar to those of C group. CONCLUSIONS: T3 action with F began at 1h for TRα and at 0.5h for TRβ. These results suggest the importance of knowing the times and doses that activate T3 receptors in adipocytes.

OBJETIVO: Examinar o efeito de diferentes doses de triiodotironina (T3) sobre a expressão gênica dos receptores TRα e TRβ em diferentes tempos. MATERIAIS E MÉTODOS: Adipócitos, 3T3-L1, foram incubados com T3 nas doses fisiológica (F, 10nM) e suprafisiológicas (SI, 100nM ou SII, 1000nM) ou veículo (controle, C) durante 0,5, 1, 6 ou 24h. mRNA dos TRs foram detectados utilizando PCR em tempo real. RESULTADOS: Níveis de TRβ aumentaram em F em 0,5h. Após 1h, níveis de TRα aumentaram em F e SI comparado ao C, enquanto TRβ diminuiu no SII comparado com C, F, e SI. Após 6h, ambos os genes foram suprimidos em todas concentrações. Em 24h, níveis de TRα e TRβ retornaram aos do C. CONCLUSÕES: Ação do T3 em F iniciou-se em 1h para TRα e 0,5h para TRβ. Esses resultados são importantes para determinar tempo inicial e dose de T3 em que os receptores de HT são ativados em adipócitos.

The epigenetic modifiers 5-aza-2'-deoxycytidine and trichostatin A influence adipocyte differentiation in human mesenchymal stem cells

Epigenetic mechanisms such as DNA methylation and histone modification are important in stem cell differentiation. Methylation is principally associated with transcriptional repression, and histone acetylation is correlated with an active chromatin state. We determined the effects of these epigenetic mechanisms on adipocyte differentiation in mesenchymal stem cells (MSCs) derived from bone marrow (BM-MSCs) and adipose tissue (ADSCs) using the chromatin-modifying agents trichostatin A (TSA), a histone deacetylase inhibitor, and 5-aza-2′-deoxycytidine (5azadC), a demethylating agent. Subconfluent MSC cultures were treated with 5, 50, or 500 nM TSA or with 1, 10, or 100 µM 5azadC for 2 days before the initiation of adipogenesis. The differentiation was quantified and expression of the adipocyte genes PPARG and FABP4 and of the anti-adipocyte gene GATA2 was evaluated. TSA decreased adipogenesis, except in BM-MSCs treated with 5 nM TSA. Only treatment with 500 nM TSA decreased cell proliferation. 5azadC treatment decreased proliferation and adipocyte differentiation in all conditions evaluated, resulting in the downregulation of PPARG and FABP4 and the upregulation of GATA2. The response to treatment was stronger in ADSCs than in BM-MSCs, suggesting that epigenetic memories may differ between cells of different origins. As epigenetic signatures affect differentiation, it should be possible to direct the use of MSCs in cell therapies to improve process efficiency by considering the various sources available.

Diferenciação de células-tronco mesenquimais derivadas do tecido adiposo em cardiomiócitos / Differentiation of adipose tissue-derived mesenchymal stem cells into cardiomyocytes

FUNDAMENTO: O potencial de renovação e proliferação dos cardiomiócitos, in vivo, é pequeno, e por isso, o músculo cardíaco apresenta limitada capacidade de repor células perdidas. Na tentativa de minimizar os danos oriundos de lesões hipóxico-isquêmicas e daquelas que acometem o sistema de condução do coração, a terapia celular com células-tronco mesenquimais (MSC) vem sendo utilizada, inclusive com cardiomiócitos diferenciados a partir de MSC. OBJETIVO: O presente trabalho comparou três protocolos distintos de indução de diferenciação objetivando a sugestão de um método viável para a diferenciação de maior número de células funcionais que expressem fenótipo cardiomiogênico. MÉTODOS: Culturas de MSC obtidas de tecido adiposo de ratos jovens da linhagem Lewis transgênicos para proteína verde fluorescente (GFP) foram submetidos a três diferentes meios de diferenciação cardiogênica: Planat-Bérnard, 5-azacitidina e meio Planat-Bérnard + 5-azacitidina e observadas quanto a expressão de marcadores celulares cardíacos. RESULTADOS: Nos três protolocos utilizados observou-se formação da proteína alfa-actinina sarcomérica no citoesqueleto das células submetidas à diferenciação, expressão de conexina 43 na membrana nuclear e citoplasmática e formação de gap junctions, necessárias para a propagação do impulso elétrico no miocárdio, contudo, em nenhum protocolo foi observada contração espontânea das células submetidas à diferenciação cardiogênica. CONCLUSÃO: A indução com 5-azacitidina proporcionou diferenciação celular cadiomiogênica efetiva e similar à encontrada com o meio Planat-Bénard e, por ser um protocolo mais simples, rápido e com menor custo torna-se o método de eleição.

BACKGROUND: Cardiomyocytes have small potential for renovation and proliferation in vivo. Consequently, the heart muscle has limited capacity of self-renewal. Mesenchymal stem cells (MSC) therapy, as well as MSC differentiated into cardiomyocytes, has been used in the attempt to minimize the effects of ischemic-hypoxic lesions and those affecting the electrical conduction system of the heart. OBJECTIVE: The present study compared three distinct protocols for induced differentiation of MSC into cardiomyocytes aimed at finding a viable method for producing a large number of functional cells expressing cardiomyogenic phenotype. METHODS: Mesenchymal stem cells were obtained from the adipose tissue of young transgenic Lewis rats expressing green fluorescent protein (GFP), and submitted to three distinct differentiation-inducing media: 1) Planat-Bérnard, 2) 5-azacytidine, and 3) Planat-Bérnard + 5-azacytidine; further, these cells were identified based on the expression of cardiac cell markers. RESULTS: All three protocols detected the expression of sarcomeric-alpha-actinin protein in the exoskeleton of cells, expression of connexin-43 in the nuclear and cytoplasmic membrane, and formation of gap junctions, which are necessary for electrical impulse propagation in the myocardium. However, no spontaneous cell contraction was observed with any of the tested protocols. CONCLUSION: Induction with 5-azacytidine provided an effective cadiomyogenic cellular differentiation similar to that obtained with Planat-Bénard media. Therefore, 5-azacytidine was the method of choice for being the simplest, fastest and lowest-cost protocol for cell differentiation.

B-cell-activating factor is a regulator of adipokines and a possible mediator between adipocytes and macrophages

3T3-L1 adipocytes express the B-cell-activating factor (BAFF) and three different BAFF receptors (BAFF-Rs). Furthermore, BAFF expression is regulated by inflammatory modulators, such as tumor necrosis factor-alpha and rosiglitazone. Here we investigated the function of BAFF in 3T3-L1 adipocytes and RAW 264.7 macrophages. We examined adipokine expression in 3T3-L1 adipocytes treated with 10 ng ml-1 BAFF. We also examined inflammatory molecule expression in RAW 264.7 macrophages treated with 10 or 100 ng ml-1 BAFF. We examined BAFF expression in the coculture of 3T3-L1 adipocytes and RAW 264.7 macrophages, as well as in white adipose tissue (WAT) of diet-induced obese (DIO) mice. We found that BAFF decreases leptin and adiponectin expression, but increases the expression of proinflammatory adipokines monocyte chemotactic protein-1, interleukin-6 (IL-6), cyclooxygenase-2 (COX-2) and haptoglobin. Coculturing the two cell types resulted in increased BAFF mRNA and protein expression, as well as modulation of BAFF-R mRNA expression in both cell types. These data indicate that BAFF might mediate adipocyte and macrophage interaction. When RAW 264.7 macrophages were treated with BAFF, BAFF-R expression was modulated as in coculture, and nitric oxide synthase and IL-6 expression increased. BAFF expression also increased in WAT of DIO mice. We propose that BAFF can regulate adipokine expression and possibly mediate adipocyte and macrophage interaction.

Engraftment of human adipose derived stem cells delivered in a hyaluronic acid preparation in mice / Implante de células tronco do tecido adiposo humano numa preparação de ácido hialurônico em camundongos

PURPOSE: To evaluate the implant of human adipose derived stem cells (ADSC) delivered in hyaluronic acid gel (HA), injected in the subcutaneous of athymic mice. METHODS: Control implants -HA plus culture media was injected in the subcutaneous of the left sub scapular area of 12 athymic mice. ADSC implants: HA plus ADSC suspended in culture media was injected in the subcutaneous, at the contra lateral area, of the same animals. With eight weeks, animals were sacrificed and the recovered implants were processed for extraction of genomic DNA, and histological study by hematoxilin-eosin staining and immunufluorescence using anti human vimentin and anti von Willebrand factor antibodies. RESULTS: Controls: Not visualized at the injection site. An amorphous substance was observed in hematoxilin-eosin stained sections. Human vimentin and anti von Willebrand factor were not detected. No human DNA was detected. ADSC implants - A plug was visible at the site of injection. Fusiform cells were observed in sections stained by hematoxilin- eosin and both human vimentin and anti von Willebrand factor were detected by immunofluorescence. The presence of human DNA was confirmed. CONCLUSION: The delivery of human adipose derived stem cells in preparations of hyaluronic acid assured cells engraftment at the site of injection.

OBJETIVO: Avaliar o implante de células tronco do tecido adiposo humano (CTTAH) em gel de ácido hialurônico (AH), injetados no tecido subcutâneo de camundongos atímicos. MÉTODOS: Implantes controle - HA com meio de cultura foram injetados no tecido subcutâneo da região infraescapular esquerda de 12 camundongos atímicos. Implantes de CTTAH: HA com CTTAH suspensas em meio de cultura foi injetado no subcutâneo da região contra lateral, dos mesmos animais. Com oito semanas, os animais foram sacrificados e os implantes recuperados foram processados para extração de DNA genômico, estudo histológico por coloração por hematoxilina eosina e imnuoflurescência utilizando anticorpos anti vimentina humana e anti fator de von Willebrand. RESULTADOS: Controles - implantes não visualizados no local da injeção. Uma substância amorfa foi observada nos cortes corados por hematoxilina eosina. Vimentina humana e fator anti von Willebrand não foram identificados. DNA humano não foi detectado. Implantes de CTTAH - Uma massa era visível no local da injeção. Células fusiformes foram observadas nos corte corados com hematoxilina eosina. Tanto vimentina humana quanto fator de von Willebrand foram identificados pela imunofluorescência. A presença de DNA humano foi confirmada. CONCLUSÃO: O implante de células tronco do tecido adiposo humano em veículo de ácido hialurônico gel assegurou a manutenção das células no local do implante.

Mitochondrial dysfunction and activation of iNOS are responsible for the palmitate-induced decrease in adiponectin synthesis in 3T3L1 adipocytes

Mitochondrial dysfunction and endoplasmic reticulum (ER) stress are considered the key determinants of insulin resistance. Impaired mitochondrial function in obese animals was shown to induce the ER stress response, resulting in reduced adiponectin synthesis in adipocytes. The expression of inducible nitric oxide synthase (iNOS) is increased in adipose tissues in genetic and dietary models of obesity. In this study, we examined whether activation of iNOS is responsible for palmitate-induced mitochondrial dysfunction, ER stress, and decreased adiponectin synthesis in 3T3L1 adipocytes. As expected, palmitate increased the expression levels of iNOS and ER stress response markers, and decreased mitochondrial contents. Treatment with iNOS inhibitor increased adiponectin synthesis and reversed the palmitate-induced ER stress response. However, the iNOS inhibitor did not affect the palmitate-induced decrease in mitochondrial contents. Chemicals that inhibit mitochondrial function increased iNOS expression and the ER stress response, whereas measures that increase mitochondrial biogenesis (rosiglitazone and adenoviral overexpression of nuclear respiratory factor-1) reversed them. Inhibition of mitochondrial biogenesis prevented the rosiglitazone-induced decrease in iNOS expression and increase in adiponectin synthesis. These results suggest that palmitate-induced mitochondrial dysfunction is the primary event that leads to iNOS induction, ER stress, and decreased adiponectin synthesis in cultured adipocytes.

Antiobesity activity of a sphingosine 1-phosphate analogue FTY720 observed in adipocytes and obese mouse model

Higher levels of body fat are associated with an increased risk for development numerous adverse health conditions. FTY720 is an immune modulator and a synthetic analogue of sphingosine 1-phosphate (S1P), activated S1P receptors and is effective in experimental models of transplantation and autoimmunity. Whereas immune modulation by FTY720 has been extensively studied, other actions of FTY720 are not well understood. Here we describe a novel role of FTY720 in the prevention of obesity, involving the regulation of adipogenesis and lipolysis in vivo and in vitro. Male C57B/6J mice were fed a standard diet or a high fat diet (HFD) without or with FTY720 (0.04 mg/kg, twice a week) for 6 weeks. The HFD induced an accumulation of large adipocytes, down-regulation of phosphorylated AMP-activated protein kinase alpha (p-AMPKalpha) and Akt (p-Akt); down-regulation of hormone-sensitive lipase (HSL), adipose triglyceride lipase (ATGL) and perilipin mRNA as well as up-regulation of phosphorylated HSL (p-HSL, Ser563) and glycogen synthase kinase 3 alpha/beta (p-GSK3alpha/beta). All these effects were blunted by FTY720 treatment, which inhibited adipogenesis and promoted lipolysis. Also, FTY720 significantly decreased lipid accumulation in maturing preadipocytes. FTY720 down-regulated the transcriptional levels of the PPARgamma, C/EBPalpha and adiponectin, which are markers of adipogenic differentiation. FTY720 significantly increased the release of glycerol and the expression of the HSL, ATGL and perilipin, which are regulators of lipolysis. These results show that FTY720 prevented obesity by modulating adipogenesis and lipolysis, and suggest that FTY720 is used for the treatment of obesity.

Avaliação citométrica dos adipócitos localizados no tecido subcutâneo da parede anterior do abdome após infiltração percutânea de CO2 / Cytometric evaluation of abdominal subcutaneous adipocytes after percutaneous CO2 infiltration

OBJETIVO: Avaliar os efeitos da infiltração de dióxido de carbono em adipócitos presentes na parede abdominal. MÉTODOS: Quinze voluntárias foram submetidas a sessões de infusão de CO2 durante três semanas consecutivas (duas sessões por semana com intervalos de dois a três dias entre cada sessão). O volume de gás carbônico infundido por sessão, em pontos previamente demarcados, foi sempre calculado com base na superfície da área a ser tratada, com volume infundido fixo de 250 mL/100cm² de superfície tratada. Os pontos de infiltração foram demarcados respeitando-se o limite eqüidistante 2cm entre eles. Em cada ponto se injetou 10mL, por sessão, com fluxo de 80mL/min. Foram colhidos fragmentos de tecido celular subcutâneo da parede abdominal anterior antes e após o tratamento. O número e as alterações histomorfológicas dos adipócitos (diâmetro médio, perímetro, comprimento, largura e número de adipócitos por campos de observação) foram mensurados por citometria computadorizada. Os resultados foram analisados com o teste t de Student pareado, adotando-se nível de significância de 5 por cento (p<0,05). RESULTADOS: Encontrou-se redução significativa no número de adipócitos da parede abdominal e na área, diâmetro, perímetro, comprimento e largura após o uso da hipercapnia (p=0,0001). CONCLUSÃO: A infiltração percutânea de CO2 reduz a população e modifica a morfologia dos adipócitos presentes na parede abdominal anterior.

OBJECTIVE: To evaluate the effects of carbon dioxide infusion to abdominal wall adipocytes. METHODS: Fifteen volunteers were subjected to sessions of CO2 infusion for three consecutive weeks (two sessions per week with intervals of two to three days between each). The volume of carbon dioxide infused per session, at points previously marked, was always calculated on the basis of surface area to be treated, with a fixed infused volume of 250 ml/100cm² of treated surface. The infiltration points were marked respecting the limit of 2cm equidistant between them. At each point 10 ml was injected per session, with a flow of 80ml/min. Fragments were collected from subcutaneous tissue of the anterior abdominal wall before and after treatment. The number and histomorphological changes of adipocytes (mean diameter, perimeter, length, width and number of adipocytes per field of observation) were measured by computerized cytometry. The results were analyzed with paired Student t test, adopting a significance level of 5 percent (p <0.05). RESULTS: There was a significant reduction in the number of adipocytes in the abdominal wall, as well as the area, diameter, perimeter, length and width of the adipocytes, after the infusion of CO2 (p = 0.0001). CONCLUSION: The percutaneous infiltration of CO2 reduces the population of adipocytes of the anterior abdominal wall and modifies their morphology.

Histomorphometric changes in the perirenal adipocytes of adrenalectomized rats treated with dexamethasone

INTRODUCTION: Prolonged steroid treatment administered to any patient can cause visceral obesity, which is associated with metabolic disease and Cushing's syndrome. Glucocorticoids have a profound negative effect on adipose tissue mass, giving rise to obesity, which in turn is regulated by the 11β-hydroxysteroid dehydrogenase type 1 enzyme. Adrenalectomized rats treated with dexamethasone exhibited an increase in visceral fat deposition but not in body weight. OBJECTIVES: The main aim of this study was to determine the effect of dexamethasone on the histomorphometric characteristics of perirenal adipocytes of adrenalectomized, dexamethasone-treated rats (ADR+Dexa) and the association of dexamethasone treatment with the expression and activity of 11 β-hydroxysteroid dehydrogenase type 1 (11 β-hydroxysteroid dehydrogenase type 1). METHODS: A total of 20 male Sprague Dawley rats were divided into 3 groups: a baseline control group (n = 6), a sham-operated group (n = 7) and an adrenalectomized group (n=7). The adrenalectomized group was given intramuscular dexamethasone (ADR+Dexa) 2 weeks post adrenalectomy, and the rats from the sham-operated group were administered intramuscular vehicle (olive oil). RESULTS: Treatment with 120 μg/kg intramuscular dexamethasone for 8 weeks resulted in a significant decrease in the diameter of the perirenal adipocytes (p<0.05) and a significant increase in the number of perirenal adipocytes (p<0.05). There was minimal weight gain but pronounced fat deposition in the dexamethasone-treated rats. These changes in the perirenal adipocytes were associated with high expression and dehydrogenase activity of 11β-hydroxysteroid dehydrogenase type 1. CONCLUSIONS: In conclusion, dexamethasone increased the deposition of perirenal fat by hyperplasia, which causes increases in the expression and dehydrogenase activity of 11 β-hydroxysteroid dehydrogenase type 1 in adrenalectomized rats.