Intracerebroventricular (ICV) administration of the hypothalamic neuropeptide neuromedin U (NMU) or the adipostat hormone leptin increases plasma ACTH and corticosterone. The relationship between leptin and NMU in the regulation of the hypothalamo-pituitary adrenal (HPA) axis is currently unknown. In this study, leptin (1 nm) significantly increased the release of CRH from ex vivo hypothalamic ...

Plasma leptin levels are elevated in obesity suggesting a pathophysiologic role of this hormone in obesity and related disorders, such as hypertension. Furthermore, despite excess leptin levels, leptin satiety action is blunted in obesity suggesting the occurrence of central leptin resistance. As leptin acts on the kidney to induce natriuresis, renal leptin receptor alterations could lead to a ...

BACKGROUND Unstable carotid plaques cause cerebral emboli. Leptin promotes atherosclerosis and vessel wall remodeling. We hypothesized that carotid atherosclerotic lesion instability is associated with local leptin synthesis. METHODS AND RESULTS Carotid endarterectomy plaques from symptomatic (n=40) and asymptomatic patients with progressive stenosis (n=38) were analyzed for local expression ...

Glucocorticoid stimulation of appetite and leptin expression conflicts with leptin inhibition of food intake and suggests that glucocorticoids reduce sensitivity to leptin. To determine if glucocorticoids impair feeding and metabolic responses to leptin, we measured leptin-induced changes in food intake, body weight, hormones, carcass fat, and hypothalamic neuropeptide Y (NPY) mRNA in adrenalec...

In mammals, leptin acts on leptin receptor (LepR) -expressing neurons in the brain to suppress food intake and stimulate whole-body metabolism. A similar action of leptin on food intake has been reported in the frog Xenopus laevis and in several bony fishes. However, the intracellular signaling and neural pathways by which leptin regulates energy balance have not been investigated outside of ma...

Pineal melatonin synthesis can be modulated by many peptides, including insulin. Because melatonin appears to alter leptin synthesis, in this work we aimed to investigate whether leptin would have a role on norepinephrine- (NE-)mediated melatonin synthesis in cultured rat pineal glands. According to our data, cultured rat pineal glands express leptin receptor isoform b (Ob-Rb). Pineal expressio...

The present study has examined the short- and long-term effects of growth hormone (GH) treatment on the leptin system and energy expenditure. Thirty male individuals with abdominal obesity were randomised to GH or placebo treatment in a 9-month, double-blind study. The dose of GH was 9.5 microg/kg, administered subcutaneously every evening. Serum leptin concentrations were measured by a human l...

Increased plasma level of leptin appears to be a ubiquitous feature of pregnant mammals. The mechanisms by which leptin levels are increased may be species specific, however, with some species upregulating adipose leptin production and others expressing leptin in the placenta. Placental leptin expression was examined in representative species of the two most abundant mammalian orders, Rodentia ...

Background & Aims: Leptin is overproduced in gastrointestinal mucosa during inflammatory processes, suggesting that mucosal cells represent sources of secreted leptin active in the lumen. The effects of leptin, acting apically from colonic epithelial cells, were analysed on dextran sulphate sodium-induced colonic inflammation in rats. Methods: We determined the effects of intracolonic leptin on...

Conjugated linoleic acid (CLA) induces insulin resistance preceded by rapid depletion of the adipokines leptin and adiponectin, increased inflammation, and hepatic steatosis in mice. To determine the role of leptin in CLA-mediated insulin resistance and hepatic steatosis, recombinant leptin was coadministered with dietary CLA in ob/ob mice to control leptin levels and to, in effect, negate the ...