BCH 3120 Lecture Notes - Lecture 18: Neuropeptide, Melanin, Thermogenin
Document Summary
Appetite regulation: hormones involved in regulating appetite, appetite regulation centers, appetite regulation signalling to peripheral tissues. Insulin: gi tract, pyy3-36, green = ghrelin. Leptin is coded by the ob gene (ob for obese) Obesity and leptin resistance: unfortunately, obese individuals become resistant to leptin. Insulin is secreted by the beta cells of the pancreas in response to high blood sugar. In the context of appetite regulation, insulin receptors can be found in the hypothalamus: when insulin binds to receptors decrease appetite, binding of insulin to its receptors leads to, decrease in activity of npy/agrp neurons. Increase in activity of pomc/cart neurons: consequence, decrease in appetite. Gastro-intestinal tract: pyy3-36: peptide yy (36 aa) is cleaved to give pyy3-36, pyy3-36 is released from the gut in a nutrient dependent manner, during fasting, low level of pyy3-36 in the blood. Following a meal, stretching of the stomach (and multiple other signals) stops the secretion of ghrelin.