Jones P M, Persaud S J, Howell S L
Biomedical Sciences Division, King's College London, Kensington, UK.
Biochem Biophys Res Commun. 1989 Aug 15;162(3):998-1003. doi: 10.1016/0006-291x(89)90772-9.
The pattern of insulin secretion from electrically permeabilised islets was studied in a perifusion system. Increases in intracellular Ca2+ stimulated insulin secretion in a dose-related manner, but the secretory response to Ca2+ was only transient, with permeabilised islets becoming rapidly insensitive to a stimulatory concentration of Ca2+. Cyclic AMP and the protein kinase C activator, phorbol 12-myristate 13-acetate (PMA), both stimulated Ca2+-induced insulin secretion from perifused permeabilised islets by increasing the maximum secretory response to Ca2+, and by maintaining elevated rates of secretion when the permeabilised islets had become insensitive to the stimulatory effects of Ca2+. These results suggest that cAMP and PMA may act partly by modifying the magnitude of the secretory response to Ca2+, and also by Ca2+-independent effects on the secretory mechanism.
在灌流系统中研究了电通透胰岛的胰岛素分泌模式。细胞内Ca2+增加以剂量相关方式刺激胰岛素分泌，但对Ca2+的分泌反应只是短暂的，通透胰岛会迅速对刺激浓度的Ca2+变得不敏感。环磷酸腺苷（cAMP）和蛋白激酶C激活剂佛波醇12-肉豆蔻酸酯13-乙酸酯（PMA），都通过增加对Ca2+的最大分泌反应，以及在通透胰岛对Ca2+的刺激作用变得不敏感时维持较高的分泌速率，来刺激灌流的通透胰岛中Ca2+诱导的胰岛素分泌。这些结果表明，cAMP和PMA可能部分通过改变对Ca2+的分泌反应幅度起作用，也通过对分泌机制的Ca2+非依赖性作用起作用。
