We previously showed that leptin inhibits bone formation by an undefined mechanism. Here, we show that hypothalamic leptin-dependent antiosteogenic and anorexigenic networks differ, and that the peripheral mediators of leptin antiosteogenic function appear to be neuronal. Neuropeptides mediating leptin anorexigenic function do not affect bone formation. Leptin deficiency results in low sympathe...

OBJECTIVE In this study, we examined changes in serum leptin levels during the estrus cycle and the role of estrogen in these changes. METHODS We measured serum leptin levels during normal estrus cycles in intact rats and estradiol-17beta (E2)-induced artificial estrus cycles in ovariectomized rats. RESULTS Serum leptin levels increased 1.6-fold from 4.2 +/- 0.2 ng/ml during diestrus stage ...

Vagal CCK-A receptors (CCKARs) and leptin receptors (LRbs) interact synergistically to mediate short-term satiety. Cocaine- and amphetamine-regulated transcript (CART) peptide is expressed by vagal afferent neurons. We sought to demonstrate that this neurotransmitter regulates CCK and leptin actions on short-term satiety. We also examined the signal transduction pathways responsible for mediati...

It is well documented that the hormone leptin regulates many central functions and that hippocampal CA1 pyramidal neurons are a key target for leptin action. Indeed, leptin modulates excitatory synaptic transmission and synaptic plasticity at the Schaffer-collateral input to CA1 neurons. However the impact of leptin on the direct temporoammonic (TA) input to CA1 neurons is not known. Here we sh...

Leptin is a hormone secreted by the gastric mucosa into the lumen of the stomach. It is present in its intact form in the intestine where it regulates nutrient absorption and intestinal mucosa integrity. We have identified the binding protein that protects leptin from the harsh conditions of the gastric juice. Immunoprecipitations and Western blot analyses demonstrated that leptin is present in...

background leptin and adiponectin are two hormones, which are released from adipocytes in order to control energy expenditure. both hormones are also involved in glucose homeostasis through control of insulin secretion from pancreatic islets. since pdx1, pparγ, and foxm1 play important roles in islets function, it is essential to understand how these genes are regulated in the islets of langerh...

Pancreastatin (PST) is a regulatory peptide containing 49 amino acids, first isolated from porcine pancreas. Intracellular and extracellular processing of the prohormone Chromogranin A (Chga) results various bioactive peptides of which PST has dysglycemic activity. PST regulates glucose, lipid, and protein metabolism in liver and adipose tissues. It also regulates the secretion of leptin and ex...

The hypothalamic-pituitary-thyroid axis is down-regulated during starvation, and falling levels of leptin are a critical signal for this adaptation, acting to suppress preprothyrotropin-releasing hormone (prepro-TRH) mRNA expression in the paraventricular nucleus of the hypothalamus. This study addresses the mechanism for this regulation, using primary cultures of fetal rat hypothalamic neurons...

Swallowing is under the control of premotoneurons located in the medullary solitary tract nucleus. While rats with transected mid-brain do not seek out food, they are able to ingest food present near the mouth, and acute food deprivation induces an increase in food intake. Leptin is a satiety signal that regulates feeding behavior. Since leptin receptors are found within the caudal brainstem, a...