Effects of topiramate, bupropion and naltrexone isolated or combined on subcutaneous adipose tissue in obese rats

ABSTRACT Objective: To evaluate the effects of combining topiramate, bupropion and naltrexone in obesity-induced rats on their weight and subcutaneous adipose tissue. Methods: A total of 40 male Wistar rats were induced to obesity for 8 weeks and the animals were divided into 8 groups: Ctr - control, G0 - Sham, G1 - oral saline solution (1.0mL/day), G2 - topiramate (20.0mg/kg) and bupropion (5.0mg/kg), G3 - naltrexone (20.0mg/kg), G4 - topiramate (20.0mg/kg), G5 - bupropion (5.0mg/kg) and G6 - topiramate (20.0mg/kg), bupropion (5.0mg/kg) and naltrexone (20.0mg/kg). During the experiment, all animals were weighed weekly. After 30 days of treatment animals were euthanized and their skin fragments were processed and stained with hematoxylin and eosin for morphological, morphometric and biochemical analyzes. Results: The only group that presented a decrease in the volume of subcutaneous adipose tissue was G3, but this decrease was not significant when compared with the other groups. The G4, the G5 and the G6 presented increased adipose tissue volume. Data showed that until the eighth week all animals increased their weight by approximately 50%. After treatment animals of all groups, except G3, increased their weight from 4% to 9% approximately. The G3 was the only group that lost weight, but this decrease was not significant. Conclusion: The medicines studied were not efficient in reducing weight in obese rats. However, it should be considered that 30-day treatment period is not enough to observe the stronger effects of these drugs.

The effect of testosterone replacement on intramedullary, inguinal and visceral fat in ovariectomized rats / Efeito da reposição de testosterona na gordura intramedular, inguinal e visceral em ratas ovariectomizadas

Abstract Objective The present article aims to evaluate the impact of testosterone treatment on the expansion of visceral, subcutaneous and intramedullary adipose tissue of ovariectomized rats and the visceral and subcutaneous fat expression of peroxisome proliferator-activated receptors (PPARs) gamma. Methods In total 48 female Wistar rats were castrated and randomly divided into 6 treatment groups: group E2 was submitted to estradiol 5 μg/day; group T, to testosterone 5 μg/day; group E2+ T, to estradiol 5 μg/day + testosterone 5 μg/day; group TT, to testosterone 30 μg/day; group E2+ TT, to estradiol 5 μg/day+ testosterone 30 μg/day; and placebo was administered to group P. After 5 weeks, the rats were euthanized, the inguinal and visceral adipose tissues were harvested, weighted, and had their PPAR gamma expression evaluated by reverse transcription quantitative polymerase chain reaction (RTqPCR). The right femurs were harvested and histologically prepared to performthe number count of the intramedullary adipocytes. Results The expansion of visceral fat tissue was much higher in the TT group when compared with other treated groups (p < 0.001). The TT group also showed a higher expansion of inguinal fat (p < 0.01), and groups E2 +T and E2+ TT presented lower growth compared to the P group (p < 0.01). The number of femur intramedullary adipocytes only showed significant differences between groups TT and E2 + TT (p < 0.05). The expression of PPAR gamma showed no differences among the groups. Conclusion The use of testosterone in high doses leads to an important expansion in both visceral and inguinal adipose tissues. Association with estradiol exerts an expansion-repressive effect on the visceral and inguinal adipose tissues.

Resumo Objetivo Este artigo tem como objetivo avaliar o impacto do tratamento com testosterona na expansão dos tecidos adiposos visceral, subcutâneo e intramedular de ratas ovariectomizadas e a expressão de receptores ativados por proliferadores de peroxissoma (RAPPs) gama nas gorduras visceral e subcutânea. Métodos No total, 48 ratas Wistar foram castradas e divididas aleatoriamente em 6 grupos de tratamento: o grupo E2 recebeu estradiol 5 μg/dia; o grupo T, testosterona 5 μg/dia; o grupo E2 + T, estradiol 5 μg/dia + testosterona 5 μg/dia; o grupo TT, testosterona 30 μg/dia; o grupo E2 + TT, estradiol 5 μg/dia + testosterona 30 μg/dia; e o grupo P recebeu placebo. Após 5 semanas, as ratas foram submetidas a eutanásia, o tecido adiposo inguinal e visceral foi coletado, pesado, e se avaliou a expressão dos RAPP gama por reação em cadeia da polimerase via transcriptase reversa quantitativa (RCP-TRq). Os ossos do fêmur direito foram colhidos e processados histologicamente para contagem de números de adipócitos intramedulares. Resultados A expansão do tecido adiposo visceral foi muito maior no grupo TT quando comparado a outros grupos tratados (p < 0,001). O grupo TT também apresentou maior expansão da gordura inguinal (p < 0,01), e os grupos E2 +T e E2 + TT apresentaram menor crescimento em relação ao grupo P (p < 0,01). O número de adipócitos intramedulares no fêmur mostrou apenas diferenças significativas entre os grupos TT e E2 + TT (p < 0,05). A expressão de RAPP gama não mostrou diferenças entre os grupos. Conclusão O uso de testosterona emaltas doses leva a uma importante expansão nos tecidos adiposos visceral e inguinal. A associação com o estradiol exerce um efeito repressivo de expansão nos tecidos adiposos visceral e inguinal.

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.

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. .