Reduction of Body Weight by Capsaicin is Associated with Inhibition of Glycerol-3-Phosphate Dehydrogenase Activity and Stimulation of Uncoupling Protein 2 mRNA Expression in Diet-induced Obese Rats

Abstract Background Obesity, a risk factor for many chronic diseases, is a potential independent risk factor for iron deficiency. Evidence has shown that chronic intermittent hypobaric hypoxia (CIHH) has protective or improved effects on cardiovascular, nervous, metabolic and immune systems. We hypothesized that CIHH may ameliorate the abnormal iron metabolism in obesity. This study was aimed to investigate the effect and the underlying mechanisms of CIHH on iron metabolism in high-fat-high-fructose-induced obese rats. Methods Six to seven weeks old male Sprague-Dawley rats were fed with different diet for 16 weeks, and according to body weight divided into four groups: control (CON), CIHH (28-day, 6-h daily hypobaric hypoxia treatment simulating an altitude of 5000 m), dietary-induced obesity (DIO; induced by high fat diet and 10% fructose water feeding), and DIO + CIHH groups. The body weight, systolic arterial pressure (SAP), Lee index, fat coefficient, blood lipids, blood routine, iron metabolism parameters, interleukin6 (IL-6) and erythropoietin (Epo) were measured. The morphological changes of the liver, kidney and spleen were examined. Additionally, hepcidin mRNA expression in liver was analyzed. Results The DIO rats displayed obesity, increased SAP, lipids metabolism disorders, damaged morphology of liver, kidney and spleen, disturbed iron metabolism, increased IL-6 level and hepcidin mRNA expression, and decreased Epo compared to CON rats. But all the aforementioned abnormalities in DIO rats were improved in DIO + CIHH rats. Conclusions CIHH improves iron metabolism disorder in obese rats possibly through the down-regulation of hepcidin by decreasing IL-6 and increasing Epo.

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Corticotropin-Releasing Hormone-Mediated Pathway of Leptin to Regulate Feeding, Adiposity, and Uncoupling Protein Expression in Mice

Endocrinology ◽

10.1210/en.2003-0301 ◽

2003 ◽

Vol 144 (8) ◽

pp. 3547-3554 ◽

Cited By ~ 57

Author(s):

Takayuki Masaki ◽

Go Yoshimichi ◽

Seiichi Chiba ◽

Tohru Yasuda ◽

Hitoshi Noguchi ◽

...

Keyword(s):

Body Weight ◽

Adipose Tissue ◽

Food Intake ◽

Mrna Expression ◽

White Adipose Tissue ◽

Energy Homeostasis ◽

Uncoupling Protein ◽

Hypothalamic Nucleus ◽

Fat Cell ◽

Brown Adipose

Abstract To examine the functional role of CRH in the regulation of energy homeostasis by leptin, we measured the effects of the CRH antagonist, α-helical CRH 8–41 (αCRH) on a number of factors affected by leptin activity. These included food intake, body weight, hypothalamic c-fos-like immunoreactivity (c-FLI), weight and histological characterization of white adipose tissue, and mRNA expressions of uncoupling protein (UCP) in brown adipose tissue (BAT) in C57Bl/6 mice. Central infusion of leptin into the lateral cerebroventricle (icv) caused significant induction of c-FLI in the paraventricular nucleus (PVN), ventromedial hypothalamic nucleus (VMH), dorsomedial hypothalamic nucleus, and arcuate nucleus. In all these nuclei, the effect of leptin on expression of cFLI in the PVN and VMH was decreased by treatment with αCRH. Administration of leptin markedly decreased cumulative food intake and body weight with this effect being attenuated by pretreatment with αCRH. In peripheral tissue, leptin up-regulated BAT UCP1 mRNA expression and reduced fat depositions in this tissue. Those changes in BAT were also decreased by treatment with αCRH. As a consequence of the effects on food intake or energy expenditure, treatment with αCRH attenuated the leptin-induced reduction of body adiposity, fat cell size, triglyceride contents, and ob mRNA expression in white adipose tissue. Taken together, these results indicate that CRH neurons in the PVN and VMH may be an important mediator for leptin that contribute to regulation of feeding, adiposity, and UCP expression.

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