BIOM 4090 Lecture Notes - Lecture 3: Repaglinide, Glucosidases, Immunopathology
24 Jan 2018
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Document Summary
Glandular organ that contains exocrine & endocrine tissue. Exocrine tissue - 99% of pancreatic mass - secretes bicarbonate & digestive enzymes in gi tract. Within exocrine tissue = nearly 1 million small islands of endocrine tissue that secrete hormones directly into the blood: produce several di . cell types that secrete di . hormones. K+/atp channel = open (basal state) > less insulin release: plasma membrane of -cell = hyperpolarized, so rate of insulin secretion from the cell is low. K+/atp channel = closed > more insulin release. When glucose is available, it enters the cell via glut2 and is metabolized to generate intracellular atp. Atp binds to and inhibits k+/atp channel, which decreases plasma membrane k+ conductance = depolarization. Depolarization activates voltage-gated ca2+ channels, resulting in an in ux of ca2+ ions. Ca2+ mediates fusion of insulin-containing secretory vesicles with the plasma membrane = insulin secretion!
