Leptin's actions are mediated via the long form of its receptor, Ob-Rb, but access to this receptor on target cells is also influenced by truncated leptin receptor isoforms Ob-Ra and Ob-Re. Plasma leptin binding activity is primarily attributed to Ob-Re, which can restrict leptin passage to extravascular tissue. In this study we investigated whether plasma leptin binding activity changes from f...

In addition to effects on appetite and metabolism, the hormone leptin is required for reproduction in mammals. Maternal plasma leptin is increased above non-pregnant levels in all mammals thus far examined, including humans. The increase in plasma leptin appears to result in part from upregulation of adipose leptin secretion (e.g., in mice), or from production and secretion of leptin from the p...

Obesity is a prevalent disorder that increases the risk for premature cardiovascular disease. The adipose tissue itself plays an active role in the regulation of fuel metabolism and energy homeostasis by expressing a number of regulatory genes, such as leptin, peroxisome proliferator-activated receptor-gamma (PPARgamma), and CCAAT/enhancer binding protein-alpha (C/EBPalpha). To study the in viv...

To determine how astrocytic leptin signaling regulates the physiological response of mice to diet-induced obesity (DIO), we performed metabolic analyses and hypothalamic leptin signaling assays on astrocytic leptin-receptor knockout (ALKO) mice in which astrocytes lack functional leptin receptor (ObR) signaling. ALKO mice and wild-type (WT) littermate controls were studied at different stages o...

BACKGROUND Leptin and adiponectin are the two key metabolic hormones secreted from adipocytes to control food intake and energy expenditure. The action of both hormones in regulation of Gonadotropin Releasing Hormone (GnRH) secretion from the hypothalamus is mediated through Kisspeptins. Kisspeptins are products of KiSS-1 gene. Leptin and adiponectin are modulators of KiSS-1 expression in the h...

Although leptin modulates immunological pathways in some species, the role of leptin as a regulator of immunocyte function in the pig has not been studied. Therefore, the primary objective of this study was to determine whether leptin influences specific immunocyte response variables in the pig in vivo or in vitro. Fifteen pigs (five pigs per treatment) were 1) injected with recombinant human l...

The expression of leptin, the ob gene product, is increased in adipose tissue in response to feeding and energy repletion, while leptin decreases food intake. Because adipose tissue gene expression is regulated by cytokines induced during infection and because infection is associated with anorexia, we tested whether induction of leptin might occur during the host response to infection. Administ...

Leptin plays a major role in coordinating the integrated response of the CNS to changes in nutritional state. Neurons within the paraventricular nucleus (PVN) of the hypothalamus express leptin receptors and receive dense innervation from leptin receptor-expressing neurons in the arcuate nucleus. To obtain new insights into the effects of circulating leptin on PVN function, we compared global t...

Leptin resistance is considered to be the primary cause of obesity. However, the cause of leptin resistance remains incompletely understood, and there is currently no cure for the leptin-resistant state. In order to identify novel drug-target molecules that could overcome leptin resistance, it would be useful to develop in vitro assay systems for evaluating leptin resistance. In this study, we ...

In hens, the ovarian follicles committed to ovulation are arranged in an ordered follicular hierarchy. In standard broiler breeders hens genetically selected for high growth rate the reproductive function is clearly dysfunctional. Feed restriction is needed during reproductive development to limit the formation of excessive numbers of ovarian yellow follicles arranged in multiple hierarchies. T...