Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 14 de 14
Filtrar
Más filtros











Base de datos
Intervalo de año de publicación
1.
An Acad Bras Cienc ; 95(suppl 2): e20230365, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37909611

RESUMEN

Obesity and depression, disorders associated with inflammation, have high incidences in women. Understanding the derangements present in the initial phase of obesity may point to factors that could help avoiding disease aggravation. The present study aimed at investigating the effects of a 6-months interdisciplinary therapy for weight loss in women with grade I obesity. Before and after the therapy, 37 middle-aged women donated blood and responded to questionnaires for depression and anxiety symptoms. Inflammatory parameters were evaluated in serum and a preliminary screening of the plasma proteome was performed. The therapy decreased anthropometric, psychological scores, and serum levels of inflammatory parameters. Depression and anxiety scores correlated positively with some inflammatory parameters. The proteomic analysis showed changes in proteins related to cholesterol metabolism and inflammatory response. Interdisciplinary therapy improves anthropometric and inflammatory statuses and ameliorating psychological symptoms. The decrease of MCP-1 levels after interdisciplinary therapy has not been reported so far, at the best of our knowledge. The present demonstration of positive associations of inflammatory markers and psychological scores indicate that these mediators may be useful to monitor psychological status in obesity. The present proteome data, although preliminary, pointed to plasma alterations indicative of improvement of inflammation after interdisciplinary therapy.


Asunto(s)
Proteoma , Proteómica , Persona de Mediana Edad , Humanos , Femenino , Obesidad , Inflamación/terapia , Inflamación/complicaciones , Estilo de Vida
2.
Artículo en Inglés | MEDLINE | ID: mdl-37573715

RESUMEN

BACKGROUND: The incapacity to store lipids in adipose tissue in Congenital Generalized Lipodystrophy (CGL) causes hypoleptinemia, increased appetite, ectopic fat deposition and lipotoxicity. CGL patients experience shortened life expectancy. The plasma lipidomic profile has not been characterized fully in CGL, nor has the extent of dietary intake in its modulation. The present work investigated the plasma lipidomic profile of CGL patients in comparison to eutrophic individuals at the fasted state and after a breakfast meal. METHOD: Blood samples from 11 CGL patients and 10 eutrophic controls were collected after 12 h fasting (T0) and 90 min after an ad libitum fat-containing breakfast (T90). The lipidomic profile of extracted plasma lipids was characterized by non-target liquid chromatography mass spectrometry. RESULTS: Important differences between groups were observed at T0 and at T90. Several molecular species of fatty acyls, glycerolipids, sphingolipids and glycerophospholipids were altered in CGL. All the detected fatty acyl molecular species, several diacylglycerols and one triacylglycerol species were upregulated in CGL. Among sphingolipids, one sphingomyelin and one glycosphingolipid species showed downregulation in CGL. Alterations in the glycerophospholipids glycerophosphoethanolamines, glycerophosphoserines and cardiolipins were more complex. Interestingly, when comparing T90 versus T0, the lipidomic profile in CGL did not change as intensely as it did for control participants. CONCLUSIONS: The present study found profound alterations in the plasma lipidomic profile of complex lipids in CGL patients as compared to control subjects. A fat-containing breakfast meal did not appear to significantly influence the CGL profile observed in the fasted state. Our study may have implications for clinical practice, also aiding to a deeper comprehension of the role of complex lipids in CGL in view of novel therapeutic strategies.


Asunto(s)
Lipodistrofia Generalizada Congénita , Humanos , Desayuno , Lipidómica , Tejido Adiposo , Lípidos
3.
Brain Sci ; 11(12)2021 Dec 02.
Artículo en Inglés | MEDLINE | ID: mdl-34942904

RESUMEN

Previous studies have shown that Ginkgo biloba extract (GbE) reduces food intake and body mass gain and regulates proteins related to lipid metabolism in obese rats. In ovariectomized rats, GbE restored the hippocampal and hypothalamic serotonergic system activity, favoring the spontaneous feeding decrement. Considering the promising hypophagic effect of GbE, this study aimed to investigate the effect of a single acute dose on hypothalamic pathways that regulate feeding behavior in male rats. Four-month-old Wistar male rats received either a single acute oral GbE dose (500 mg/kg) or vehicle. Food intake and body mass were measured after 1, 4, 12, and 24 h. Rats were euthanized, and hypothalami were removed for mRNA quantification of anorexigenic (POMC/CART) and orexigenic (AgRP/NPY) neuropeptides, leptin/serotonin receptors (5HT1A, 5HT1B, 5HT2C), and serotonin transporters. We also investigated POMC, 5-HT1B, and 5-HT2C protein levels. A single acute GbE dose induced the hypothalamic POMC, CART, and 5-HT2C gene expression but failed to modify orexigenic effectors. No alterations in food intake, body mass, and hypothalamic protein levels were observed. In summary, the present findings demonstrate the rapid stimulation of pivotal hypothalamic anorexigenic pathways in response to a single GbE administration, reinforcing the GbE hypophagic activity. However, more studies are necessary to evaluate its potential as an appetite modulator.

4.
Physiol Rep ; 8(4): e14380, 2020 02.
Artículo en Inglés | MEDLINE | ID: mdl-32109344

RESUMEN

The effect of fish oil (FO) treatment on high-fat (HF) diet-induced obesity and metabolic syndrome was addressed by analyzing dysfunctions in cells of different adipose depots. For this purpose, mice were initially induced to obesity for 8 weeks following a treatment with FO containing high concentration of EPA compared to DHA (5:1), for additional 8 weeks (by gavage, 3 times per week). Despite the higher fat intake, the HF group showed lower food intake but higher body weight, glucose intolerance and insulin resistance, significant dyslipidemia and increased liver, subcutaneous (inguinal-ING) and visceral (retroperitoneal-RP) adipose depots mass, accompanied by adipocyte hypertrophy and decreased cellularity in both adipose tissue depots. FO treatment reversed all these effects, as well as it improved the metabolic activities of isolated adipocytes, such as glucose uptake and lipolysis in both depots, and de novo synthesis of fatty acids in ING adipocytes. HF diet also significantly increased both the pro and anti-inflammatory cytokines expression by adipocytes, while HF + FO did not differ from control group. Collectively, these data show that the concomitant administration of FO with the HF diet is able to revert metabolic changes triggered by the diet-induced obesity, as well as to promote beneficial alterations in adipose cell activities. The main mechanism underlying all systemic effects involves direct and differential effects on ING and RP adipocytes.


Asunto(s)
Adipocitos/metabolismo , Aceites de Pescado/uso terapéutico , Síndrome Metabólico/tratamiento farmacológico , Obesidad/etiología , Adipocitos/efectos de los fármacos , Adipoquinas/sangre , Adipoquinas/metabolismo , Animales , Células Cultivadas , Dieta Alta en Grasa/efectos adversos , Aceites de Pescado/administración & dosificación , Aceites de Pescado/farmacología , Glucosa/metabolismo , Lipólisis , Masculino , Síndrome Metabólico/etiología , Ratones , Ratones Endogámicos C57BL , Obesidad/complicaciones
5.
Front Pharmacol ; 10: 686, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31258482

RESUMEN

The rapid increase in the number of individuals with obesity, over the past four decades, is triggered by a number of complex interactions among factors. Despite the plethora of treatments available, side effects are commonly observed and, in this context, herbal medicines have been employed as an alternative form of therapy. Ginkgo biloba extract (GbE) has been described as a promising new pharmacological approach to treat obesity. In order to better comprehend the mechanisms involved with this potential effect, the present study evaluated the effects of GbE treatment on diet-induced obese rats, focusing on the proteome and the oxidative stress defense system of visceral adipose tissue. After 14 days treatment, GbE significantly modulated 25 proteins. Retroperitoneal adipose tissue of treated animals exhibited higher amounts of proteins associated with adipogenesis (decorin), carbon metabolism and mitochondrial function (citrate synthase), and a concomitant reduction in adipocyte hypertrophy. In parallel, GbE down-regulated proteins involved in oxidative stress (peroxiredoxin) and the inflammatory response (complement C3, mast cell protease 1, and Ig gamma-2B chain C region). Moreover, also related to oxidative stress defense, GbE stimulated catalase activity, reduced malondialdehyde levels (lipid peroxidation indicator), and increased lactoylglutathione lyase levels. It was concluded that GbE acts as an antioxidant agent, and improved the proteome profile and oxidative stress response in the adipose tissue of diet-induced obese rats.

6.
Artículo en Inglés | MEDLINE | ID: mdl-31133986

RESUMEN

Exacerbated expansion of adipose tissue seen in diet-induced obesity leads to endocrine dysfunction and disturbance in adipokine secretion, with such abnormal profile positively associated with type 2 diabetes and other mild chronic inflammatory conditions. Ginkgo biloba extract (GbE), a mixture of polyphenols with antioxidant properties, has been recently investigated in a variety of experimental models of endocrine dysfunction, with several potentially beneficial effects identified, including improvement in insulin sensitivity in obese rats, and reduction of weight gain in ovariectomy-induced obesity and diet-induced obesity. The aim of this study was to investigate in high fat diet-induced obese male rats the effects of GbE supplementation for 2 weeks on adipocyte volume and adipose tissue lipid accumulation. GbE supplementation was effective in reducing energy intake in obese rats compared to the saline-treated placebo group. Epididymal adipocyte volume was reduced in GbE-supplemented rats, as were epididymal [1-14C]-acetate incorporation into fatty acids, perilipin (Plin 1) and fatty acid synthase (Fasn) mRNA, and FAS protein levels. Adipocyte hypertrophy in obesity is associated with insulin resistance, and in the present study we observed a reduction in the adipocyte volume of GbE-supplemented obese rats to dimensions equivalent to adipocytes from non-obese rats. GbE supplementation significantly reduced acetate accumulation and tended to reduce [3H]-oleate incorporation, into epididymal adipose tissue, suggesting a potentially anti-obesogenic effect in longer term therapies. Further studies that investigate the effects of GbE supplementation in other experimental models are required to fully elucidate its suggested beneficial effects on mild chronic inflammatory conditions.

7.
Front Pharmacol ; 8: 605, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-28928661

RESUMEN

Menopause is associated with increased risk to develop obesity but the mechanisms involved are not fully understood. We have shown that Ginkgo biloba extract (GbE) improved diet-induced obesity. Since GbE might be effective in the treatment of obesity related to menopause, avoiding the side effects of hormone replacement therapy, we investigated the effect of GbE on hypothalamic systems controlling energy homeostasis. Wistar rats were either ovariectomized (OVX) or Sham-operated. After 2 months, either 500 mg.kg-1 of GbE or vehicle were administered daily by gavage for 14 days. A subset of animals received an intracerebroventricular (i.c.v.) injection of serotonin (300 µg) or vehicle and food intake was measured after 12 and 24 h. Another subset was submitted to in vivo microdialysis and 5-HT levels of the medial hypothalamus were measured by high performance liquid chromatography, before and up to 2 h after the administration of 500 mg.kg-1 of GbE. Additional animals were used for quantification of 5-HT1A, 5-HT1B, 5-HT2C, 5-HTT, and pro-opiomelanocortin hypothalamic protein levels by Western blotting. OVX increased food intake and body weight and adiposity while GbE attenuated these alterations. i.c.v. serotonin significantly reduced food intake in Sham, Sham + GbE, and OVX + GbE groups while it failed to do so in the OVX group. In the OVX rats, GbE stimulated 5-HT microdialysate levels while it reduced hypothalamic 5-HTT protein levels. The results indicate that GbE improved the ovariectomy-induced resistance to serotonin hypophagia, at least in part through stimulation of the hypothalamic serotonergic activity. Since body weight gain is one of the most important consequences of menopause, the stimulation of the serotonergic transmission by GbE may represent a potential alternative therapy for menopause-related obesity.

8.
Proteome Sci ; 10(1): 26, 2012 Apr 20.
Artículo en Inglés | MEDLINE | ID: mdl-22519962

RESUMEN

BACKGROUND: The hypothalamus plays a pivotal role in numerous mechanisms highly relevant to the maintenance of body homeostasis, such as the control of food intake and energy expenditure. Impairment of these mechanisms has been associated with the metabolic disturbances involved in the pathogenesis of obesity. Since rodent species constitute important models for metabolism studies and the rat hypothalamus is poorly characterized by proteomic strategies, we performed experiments aimed at constructing a two-dimensional gel electrophoresis (2-DE) profile of rat hypothalamus proteins. RESULTS: As a first step, we established the best conditions for tissue collection and protein extraction, quantification and separation. The extraction buffer composition selected for proteome characterization of rat hypothalamus was urea 7 M, thiourea 2 M, CHAPS 4%, Triton X-100 0.5%, followed by a precipitation step with chloroform/methanol. Two-dimensional (2-D) gels of hypothalamic extracts from four-month-old rats were analyzed; the protein spots were digested and identified by using tandem mass spectrometry and database query using the protein search engine MASCOT. Eighty-six hypothalamic proteins were identified, the majority of which were classified as participating in metabolic processes, consistent with the finding of a large number of proteins with catalytic activity. Genes encoding proteins identified in this study have been related to obesity development. CONCLUSION: The present results indicate that the 2-DE technique will be useful for nutritional studies focusing on hypothalamic proteins. The data presented herein will serve as a reference database for studies testing the effects of dietary manipulations on hypothalamic proteome. We trust that these experiments will lead to important knowledge on protein targets of nutritional variables potentially able to affect the complex central nervous system control of energy homeostasis.

9.
Cell Mol Neurobiol ; 30(7): 1025-33, 2010 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-20526668

RESUMEN

Hypothalamic serotonin inhibits food intake and stimulates energy expenditure. High-fat feeding is obesogenic, but the role of polyunsaturated fats is not well understood. This study examined the influence of different high-PUFA diets on serotonin-induced hypophagia, hypothalamic serotonin turnover, and hypothalamic protein levels of serotonin transporter (ST), and SR-1B and SR-2C receptors. Male Wistar rats received for 9 weeks from weaning a diet high in either soy oil or fish oil or low fat (control diet). Throughout 9 weeks, daily intake of fat diets decreased such that energy intake was similar to that of the control diet. However, the fish group developed heavier retroperitoneal and epididymal fat depots. After 12 h of either 200 or 300 µg intracerebroventricular serotonin, food intake was significantly inhibited in control group (21-25%) and soy group (37-39%) but not in the fish group. Serotonin turnover was significantly lower in the fish group than in both the control group (-13%) and the soy group (-18%). SR-2C levels of fish group were lower than those of control group (50%, P = 0.02) and soy group (37%, P = 0.09). ST levels tended to decrease in the fish group in comparison to the control group (16%, P = 0.339) and the soy group (21%, P = 0.161). Thus, unlike the soy-oil diet, the fish-oil diet decreased hypothalamic serotonin turnover and SR-2C levels and abolished serotonin-induced hypophagia. Fish-diet rats were potentially hypophagic, suggesting that, at least up to this point in its course, the serotonergic impairment was either compensated by other factors or not of a sufficient extent to affect feeding. That fat pad weight increased in the absence of hyperphagia indicates that energy expenditure was affected by the serotonergic hypofunction.


Asunto(s)
Grasas Insaturadas en la Dieta/farmacología , Ingestión de Alimentos/efectos de los fármacos , Aceites de Pescado/farmacología , Serotonina/metabolismo , Tejido Adiposo/anatomía & histología , Animales , Dieta , Aceites de Pescado/administración & dosificación , Humanos , Ácido Hidroxiindolacético/química , Ácido Hidroxiindolacético/metabolismo , Hipotálamo/química , Hipotálamo/metabolismo , Infusiones Intraventriculares , Masculino , Tamaño de los Órganos , Distribución Aleatoria , Ratas , Ratas Wistar , Receptor de Serotonina 5-HT1B/metabolismo , Receptor de Serotonina 5-HT2C/metabolismo , Serotonina/administración & dosificación , Serotonina/química , Proteínas de Transporte de Serotonina en la Membrana Plasmática/metabolismo , Aceite de Soja/administración & dosificación , Aceite de Soja/farmacología
10.
Br J Nutr ; 101(8): 1255-61, 2009 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-18786279

RESUMEN

We have previously shown that adult female rats exposed to intra-uterine malnutrition were normophagic, although obese and resistant to insulin-induced hypophagia. The present study aimed at examining aspects of another important catabolic component of energy homeostasis control, the hypothalamic serotonergic function, which inhibits feeding and stimulates energy expenditure. Pregnant dams were fed ad libitum or were restricted to 50 % of ad libitum intake during the first 2 weeks of pregnancy. Control and restricted 4-month-old progeny were studied. The restricted rats had increased body adiposity with normal daily food intake but failed to respond with hypophagia to an intracerebroventricular injection of serotonin (5-hydroxytryptamine; 5-HT). Stimulation, by food ingestion, of extracellular levels of serotonin in medial hypothalamus microdialysates was more pronounced and lasted longer in the restricted than in the control rats. In the restricted group, hypothalamic levels of 5-HT 2C receptor protein tended to be reduced (P = 0.07) while the levels of 5-HT1B receptor and serotonin transporter proteins were significantly elevated (36 and 79 %, respectively). In conclusion, female rats undernourished in utero had normophagic obesity as adults but had an absence of serotonin-induced hypophagia and low hypothalamic levels of the 5-HT 2C receptor. Compensatory adaptations for the functional serotonergic impairment were evidenced, such as an enhanced release of serotonin in response to a meal allied to up-regulated hypothalamic 5-HT1B and transporter expression. Whether these compensations will persist in later life warrants further investigation. Moreover, it cannot be ruled out that the serotonergic component of energy expenditure was already impaired, thus contributing to the observed body-fat phenotype.


Asunto(s)
Desnutrición/fisiopatología , Obesidad/embriología , Efectos Tardíos de la Exposición Prenatal , Fenómenos Fisiologicos de la Nutrición Prenatal/fisiología , Serotonina/fisiología , Animales , Peso Corporal/fisiología , Ingestión de Alimentos/efectos de los fármacos , Ingestión de Alimentos/fisiología , Femenino , Enfermedades Fetales/fisiopatología , Hipotálamo/metabolismo , Microdiálisis/métodos , Obesidad/etiología , Obesidad/fisiopatología , Embarazo , Ratas , Ratas Wistar , Serotonina/farmacología
11.
Nutrition ; 22(11-12): 1152-61, 2006.
Artículo en Inglés | MEDLINE | ID: mdl-17029904

RESUMEN

OBJECTIVE: We evaluated whether insulin hypophagia and hypothalamic signaling are affected in adult rats exposed to intrauterine undernutrition. METHODS: Pregnant rats ate ad libitum throughout pregnancy and lactation (control, C) or 50% of control intake in the first 2 wk of pregnancy (restricted, R). Four-month-old C and R progeny received insulin or vehicle intracerebroventricular injections for evaluation of 24-h food intake, hypothalamic insulin receptor (IR), and IR substrate-1 (IRS-1) protein content and tyrosine phosphorylation, pp185 phosphorylation, and IRS-1 association with phosphatidylinositol 3-kinase (PI3-K). RESULTS: With respect to males, R males had normal body composition and insulin-induced hypophagia. IR protein levels were lower but IR phosphorylation was higher in R than in C males. IRS-1 levels and phosphorylation were similar between C and R males, insulin stimulated an IRS-1/PI3-K association in C but not in R males, and pp185 phosphorylation was higher in R than in C males. For females, body fat and serum leptin were elevated in R females. Insulin inhibited food intake in C but not in R females. Insulin-induced IR phosphorylation and protein levels of IR and IRS-1 were higher in R than in C females. However, IRS-1 and pp185 phosphorylation and IRS-1/PI3-K association were significantly stimulated by insulin in C but not in R females. CONCLUSIONS: Female adult rats exposed to intrauterine undernutrition had increased adiposity, marked impairment of hypothalamic insulin signaling, and loss of insulin-induced hypophagia. These disturbances were less severe or even absent in male progeny. The findings show that female progeny are more susceptible than their male siblings to the effects of maternal malnutrition.


Asunto(s)
Animales Recién Nacidos/metabolismo , Hipotálamo/fisiopatología , Insulina/metabolismo , Desnutrición/fisiopatología , Fenómenos Fisiologicos Nutricionales Maternos/fisiología , Receptor de Insulina/metabolismo , Animales , Composición Corporal/fisiología , Dieta Reductora , Ingestión de Alimentos/fisiología , Femenino , Hipotálamo/metabolismo , Inyecciones Intraventriculares , Proteínas Sustrato del Receptor de Insulina , Péptidos y Proteínas de Señalización Intracelular , Lactancia/fisiología , Masculino , Desnutrición/sangre , Desnutrición/metabolismo , Fosfoproteínas/metabolismo , Fosforilación , Embarazo , Preñez/metabolismo , Preñez/fisiología , Efectos Tardíos de la Exposición Prenatal , Ratas , Ratas Wistar , Factores Sexuales , Transducción de Señal/fisiología
12.
Nutrition ; 22(7-8): 820-9, 2006.
Artículo en Inglés | MEDLINE | ID: mdl-16815496

RESUMEN

OBJECTIVE: Using rats we examined whether maternal intake of hydrogenated fat rich in trans fatty acids affects brain fatty acid profile, hypothalamic content of insulin receptor and insulin receptor substrate-1 proteins, and the hypophagic effect of centrally administered insulin in 3-mo-old male progeny. METHODS: Throughout pregnancy and lactation, Wistar rats ate isocaloric/normolipidic diets with soybean oil (control) or soybean oil-derived hydrogenated fat (trans diet) as a fat source. Upon weaning, the trans offspring continued on the trans diet (trans group) or were switched to a control diet (trans-control group). RESULTS: Compared with control rats, trans rats had lower brain levels of eicosapentaenoic acid. Compared with trans rats, trans-control rats had increased levels of total polyunsaturated fatty acids and arachidonic acid and decreased levels of trans fatty acids, saturated fatty acids, and monounsaturated fatty acids. Insulin receptor and insulin receptor substrate-1 levels were significantly lower (44% and 38%, respectively) in trans than in control rats. In trans-control rats, insulin receptor was 26% lower (P < 0.05), whereas insulin receptor substrate-1 was 50% lower, than in control rats. Insulin decreased 24-h feeding in control (27%) and trans (38%) rats but failed to do so in trans-control rats. The latter group had increased serum glucose levels. CONCLUSIONS: The data suggest that the early (intrauterine/perinatal) exposure to hydrogenated fat rich in trans fatty acids programmed the hypothalamic feeding control mechanisms. As young adults, only trans-control animals showed loss of insulin-induced hypophagia, indicating that the mismatch between early and later nutritional environments was relevant. However, the trans group also showed signs of altered appetite signaling mechanisms, suggesting that the early adaptations may have deleterious consequences later in life.


Asunto(s)
Grasas de la Dieta/administración & dosificación , Ingestión de Alimentos/efectos de los fármacos , Insulina/farmacología , Lactancia , Efectos Tardíos de la Exposición Prenatal , Ácidos Grasos trans/administración & dosificación , Animales , Regulación del Apetito/efectos de los fármacos , Glucemia/análisis , Química Encefálica , Grasas de la Dieta/análisis , Ácido Eicosapentaenoico/análisis , Ácidos Grasos/análisis , Femenino , Hidrogenación , Hipotálamo/química , Hipotálamo/efectos de los fármacos , Hipotálamo/fisiología , Insulina/administración & dosificación , Insulina/sangre , Proteínas Sustrato del Receptor de Insulina , Fosfoproteínas/análisis , Embarazo , Ratas , Ratas Wistar , Receptor de Insulina/análisis , Aceite de Soja/administración & dosificación , Aceite de Soja/química
13.
Nutr Neurosci ; 7(4): 235-9, 2004 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-15682650

RESUMEN

Endogenous neuropeptide Y (NPY) levels increase during fasting and before dark onset in rats. The feeding that follows these states elicits the release of serotonin in the lateral hypothalamus (LH), as part of the physiological mechanisms controlling satiety. With the hypothesis that exogenous NPY-induced feeding should also stimulate serotonin, we measured its release in the LH of non-fasted rats, which received a single intracerebroventricular injection of either 1.0, 2.0, or 5.0 microg of NPY. After 1.0 microg, the cumulative 2-h intake was of 13 g and serotonin release significantly increased (54% peak). These feeding and serotonergic responses were highly similar to the ones we observed in a previous study, in which feeding followed an overnight fast. Thus, the 1.0 microg NPY dose stimulated intake while preserving the normal serotonergic activation. Contrarily, as the NPY dose was increased to either 2.0 or 5.0 microg, the cumulative 2-h intakes were of 18 g, but the serotonergic stimulation was absent. It is suggested that this dual NPY effect relies on a finely tuned control mechanism, reflecting the existence of a narrow range of NPY levels within which the serotonergic stimulation resembles those seen in physiological states.


Asunto(s)
Ingestión de Alimentos/efectos de los fármacos , Hipotálamo/efectos de los fármacos , Hipotálamo/metabolismo , Serotonina/metabolismo , Animales , Relación Dosis-Respuesta a Droga , Ayuno , Masculino , Neuropéptido Y , Ratas
14.
Brain Res Bull ; 58(4): 363-9, 2002 Aug 15.
Artículo en Inglés | MEDLINE | ID: mdl-12183012

RESUMEN

Corticosteroids influence energy homeostasis through centrally-mediated stimulation of energy intake and inhibition of expenditure, while central serotonin (5-HT) has opposite effects. Both serotonergic dysfunction and high glucocorticoid levels may be relevant in obesity. The neurotoxin monosodium glutamate (MSG) induces a non-hyperphagic and hypometabolic obesity with hypercorticosteronemia. We investigated the influence of corticosterone levels on the serotonergic system of MSG-obese and control rats. Applying microdialysis, we found a similar feeding-induced stimulation of serotonin release in the lateral hypothalamus (LH) in sham-adrenalectomized control and MSG rats. The concomitant serum corticosterone variations were markedly distinct between them, in that an increase occurred in the control group, while the initially high levels of the MSG rats decreased with feeding. It is suggested that this lowering of corticosterone prevented a higher serotonergic activation, which would lead to a higher meal-induced thermogenesis and a better adequation of the caloric intake to a low metabolism. Adrenalectomy completely abolished the feeding-evoked serotonergic stimulation in both groups. This observation demonstrates that glucocorticoids are necessary for food intake to acutely stimulate 5-HT release and indicates that serotonergic activity in the LH is not likely to participate in the adrenalectomy-induced attenuation of the MSG-obesity.


Asunto(s)
Adrenalectomía , Ingestión de Alimentos/fisiología , Hipotálamo/metabolismo , Obesidad/metabolismo , Serotonina/metabolismo , Glutamato de Sodio , Adrenalectomía/estadística & datos numéricos , Animales , Corticosterona/sangre , Ingestión de Alimentos/efectos de los fármacos , Masculino , Obesidad/sangre , Obesidad/inducido químicamente , Obesidad/fisiopatología , Ratas , Ratas Wistar , Glutamato de Sodio/efectos adversos
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA