Leptin is a 16 kDa protein mainly produced by adipose tissue in proportion to adipose tissue mass. Originally thought to be a satiety factor, leptin is a pleiotropic molecule. In addition to playing a role in energy regulation, leptin also regulates endocrine and immune functions. Both the structure of leptin and that of its receptor suggest that leptin might be classified as a cytokine. The se...

A specific leptin RIA was developed to assess concentrations of leptin in ovine plasma, and was shown to be efficient with bovine and caprine plasma. A specific, high-affinity antibody was generated against recombinant ovine leptin which, when used in a competitive leptin RIA, provided valid estimates of linearity (r=+0.989-0.998), recovery (102%), repeatability (13%) and limit of sensitivity (...

Basic lipophilic drugs such as propranolol and lidocaine are strongly bound by alpha(1)-acid glycoprotein, also called orosomucoid. Although the liver is known to rapidly clear plasma protein-bound propranolol or lidocaine, it is generally regarded that peripheral tissues, such as brain or heart, are only exposed to the small fraction of drug that is free or dialyzable in vitro. The "free drug"...

Leptin is an adipocyte-derived hormone that has been implicated to serve as a metabolic signal to the reproductive axis. The role of leptin in pubertal maturation, however, has been a much-debated topic. We have previously reported that leptin serves as a permissive signal to the onset of puberty in the female rat. In an attempt to further understand the mechanics of leptin during pubertal matu...

Objective(s): Genistein, as a phytoestrogen found in legumes, has several biological activities in general and anti-diabetic activity particularly. In this study, we investigated the effect of genistein on proteins involved in β-cell proliferation, survival and apoptosis to further reveal its anti-diabetic potential in the ovariectomized diabetic rat. Materials and Methods: We used three-month-...

Rodent leptin is secreted by adipocytes and acutely regulates appetite and chronically regulates body weight. Mechanisms for leptin secretion in cultured adipocytes were investigated. Acutely, energy-producing substrates stimulated leptin secretion about twofold. Biologically inert carbohydrates failed to stimulate leptin secretion, and depletion of intracellular energy inhibited leptin release...

SH2B1 (previously named SH2-B), a cytoplasmic adaptor protein, binds via its Src homology 2 (SH2) domain to a variety of protein tyrosine kinases, including JAK2 and the insulin receptor. SH2B1-deficient mice are obese and diabetic. Here we demonstrated that multiple isoforms of SH2B1 (alpha, beta, gamma, and/or delta) were expressed in numerous tissues, including the brain, hypothalamus, liver...