Rats selectively bred to develop diet-induced obesity (DIO) have an early onset reduction in the sensitivity of their ventromedial hypothalamic nucleus (VMN) neurons to leptin compared with diet-resistant (DR) rats. This reduced sensitivity includes decreased leptin receptor (Lepr-b) mRNA expression, leptin receptor binding, leptin-induced phosphorylation of STAT3 (pSTAT3), and impaired leptin ...

Rink C, Roy S, Khanna S, Rink T, Bagchi D, Sen CK. Transcriptome of the subcutaneous adipose tissue in response to oral supplementation of type 2 Lepr obese diabetic mice with niacinbound chromium. Physiol Genomics 27: 370–379, 2006. First published August 29, 2006; doi:10.1152/physiolgenomics.00071.2006.— The effects of oral niacin-bound chromium (NBC) supplementation on the subcutaneous fat t...

Leptin, the key regulator of mammalian energy balance, has been at the center of a great controversy in avian biology for the last 15 years since initial reports of a putative leptin gene (LEP) in chickens. Here, we characterize a novel LEP in rock dove (Columba livia) with low similarity of the predicted protein sequence (30% identity, 47% similarity) to the human ortholog. Searching the Seque...

Hepatic steatosis is the accumulation of fat in liver cells. Insulin resistance (IR) occurs when normal amounts of insulin do not stimulate insulin activity in cells. Both conditions have been described in hepatitis C virus (HCV) infection and are thought to be biologically related. This study examined the association of genetic variants with steatosis and IR among 167 African Americans and 184...

Methods and Results-—We investigated whether dietary salt restriction might ameliorate cardiac injury in DahlS.Z-Lepr/Lepr (DS/obese) rats, which are derived from a cross between Dahl salt-sensitive and Zucker rats and represent a model of metabolic syndrome. DS/obese rats were fed a normal-salt (0.36% NaCl in chow) or low-salt (0.0466% NaCl in chow) diet from 9 weeks of age and were compared w...

Linkage mapping in a backcross of {Brown Norway [BN/Crl (BN)] × ZUC-Lepr (faSte) (ZUC)} × ZUC identified a male-specific quantitative trait locus (QTL) for urinary albumin excretion (UAE) on rat chromosome 1. A homozygous ZUC.BN-(D1Rat42-D1Rat90)/Ste congenic was produced containing BN donor alleles from 135 to 276 Mb from chromosome 1 on the ZUC background. We observed threefold higher urinary...

Leptin receptors (LepRs) expressed in the midbrain contribute to the action of leptin on feeding regulation. The midbrain neurons release a variety of neurotransmitters including dopamine (DA), glutamate and GABA. However, which neurotransmitter mediates midbrain leptin action on feeding remains unclear. Here, we showed that midbrain LepR neurons overlap with a subset of dopaminergic, GABAergic...

Objectives: Cold exposure induces hyperphagia to counteract fat loss related to lipid mobilization and thermogenic activation. The aim of this study was investigate on the molecular mechanisms involved in cold-induced compensatory hyperphagia. Methods: We analyzed the effect of cold exposure on gene expression of orexigenic and anorexigenic peptides, and of leptin signaling-related genes in the...

The acute-phase protein orosomucoid (ORM) exhibits a variety of activities in vitro and in vivo, notably modulation of immunity and transportation of drugs. We found in this study that mice lacking ORM1 displayed aberrant energy homeostasis characterized by increased body weight and fat mass. Further investigation found that ORM, predominantly ORM1, is significantly elevated in sera, liver, and...

INTRODUCTION Longevity is commonly associated with good health and with delayed onset of age-related diseases with usually benign course. Leptin (LEP) significantly affects metabolism and numerous functions of the organism. To find out if extreme longevity and its phenotype are associated with genetic variants of leptin and leptin receptor (LEPR) genes, we analysed the frequencies of the -2548 ...