Endocrine Abstracts

Background: Serotonergic signalling has been implicated in numerous hypothalamic functions including circadian rhythmicity, feeding and the modulation of neuroendocrine systems. In spite of the importance of these functions, the neuroanatomy of the serotonergic system in the human hypothalamus is still unknown.Aim and methods: To increase insight in hypothalamic serotonin signalling in humans, we investigated the distribution of serotonin transporters (S...

During fasting neuropeptide Y (NPY) neurons in the mediobasal hypothalamus are activated to increase food intake and to conserve energy. Under conditions of food deprivation, lipid metabolism plays an important role in providing fuel for muscle. We investigated if central NPY affects VLDL-TAG secretion directly via the autonomic nervous system. We measured VLDL-TAG secretion in Wistar rats by an intravenous bolus of tyloxapol to inhibit uptake of triglycerides by peripheral ti...

Background: Previous studies reported that direct injection of estrogen (E2) into different hypothalamic nuclei affects food intake, body weight and locomotor activity. We hypothesized that E2 signaling in the hypothalamus regulates glucose metabolism independently of circulating estrogen levels.Methods: We investigated the effects of hypothalamic estrogen administration on basal glucose production as well as on hepatic and peripher...

Background: Shift workers and rodents with clock gene mutations show increased risk of metabolic syndrome and type 2 diabetes (T2DM). Conversely, obesity and T2DM are related to circadian disturbances in humans and rodents. The circadian release of adipokines from white adipose tissue (WAT) plays a pivotal role in energy metabolism. Its regulatory mechanism is unclear at present.Aim: To determine the daily expression patterns of genes involved in circadi...

Background: Recently, we showed that rats on a free-choice high-fat high-sugar (fcHFHS) diet became rapidly obese and developed glucose intolerance within a week. Interestingly, rats on a free-choice high-fat diet (fcHF), although equally obese and hyperphagic as rats on a fcHFHS diet, did not develop glucose intolerance. Glucose tolerance was also unaffected in rats on a free-choice high-sugar diet, although they consumed more liquid sugar than rats on a fcHFHS diet. Hence, t...

Background: Rats on a free-choice (fc) diet of saturated fat and liquid sugar in addition to chow (fcHFHS) overeat persistently, and show increased hypothalamic neuropeptide Y and decreased melanocortin signaling, which reflects a hunger state despite hyperphagia. This response is specific for a fcHFHS diet, because when given the choice between fat and chow (fcHF) or between liquid sugar and chow (fcHS) hyperphagia is not observed. Because leptin signaling is important for th...