Thiopentone-induced insulin secretion via activation of IP3-sensitive calcium stores in rat pancreatic beta cells
会议名称：《中国生理学会第23届全国会员代表大会暨生理学学术大会》
会议日期：2010年
学科分类：1001[医学-基础医学(可授医学、理学学位)] 10[医学]
摘 要：Although glucose-elicited insulin secretion depends on Ca entry through voltage-gated Ca channels in the cell membrane of pancreatic beta cells,there are also ample evidence for an important role of intracellular Ca stores,particularly in relation to biochemical *** report here that thiopentone stimulates insulin secretion from cultured primary rat pancreatic beta cells,and the mechanisms were investigated by measurements of whole-cell K and Ca currents,membrane potential,the cytoplasmic Ca concentration([Ca];) and membrane capacitance. Thiopentone(300μmol/L) reduces both whole-cell K currents and Ca currents to 60%,while it only depolarizes beta cell membrane potential in 20%pancreatic beta *** the meantime,the anesthetic evokes[Ca] increase in beta cells in the presence or absence of extracellular *** data indicate that thiopentone-induced insulin release occurs by mechanisms that are independent of Ca entry across the cell *** thiopentone-induced [Ca] rise in cultured rat beta cells is sensitive to heparin(0.1 mg/mL),a drug that inhibits the binding of IP3 and IP3 receptor;thapsigargin(1μmol/L),a blocker of the endoplasmic reticulum(ER) Ca pump;and U73122,a PLC *** conclude that the[Ca];required for thiopentone-induced insulin secretion is released from IP3-sensitive Ca store.