Hughes S J, Christie M R, Ashcroft S J
Mol Cell Endocrinol. 1987 Apr;50(3):231-6. doi: 10.1016/0303-7207(87)90021-9.
Insulin secretion stimulated by 10 mM glucose was potentiated by forskolin, an activator of adenyl cyclase, by acetyl choline which may enhance turnover of inositol phospholipids, and by tetradecanoyl phorbol acetate (TPA), an activator of protein kinase C. None of these agents initiated insulin secretion in the presence of 2 mM glucose. Glucose-stimulated insulin secretion was markedly dependent on the concentration of extracellular Ca2+: at or below 10 microM Ca2+ no insulin secretion was evoked by glucose in freshly isolated islets. The threshold Ca2+ requirement was increased after culture of islets for 44 h. In both fresh and cultured islets the presence of a potentiator of secretion produced both a marked increase in the maximum rate of glucose-stimulated insulin secretion and a lowering of the requirement for extracellular Ca2+. Thus potentiation of insulin release involves an increase in the sensitivity of the B cell to Ca2+.
10 mM葡萄糖刺激的胰岛素分泌可被腺苷酸环化酶激活剂福斯高林、可能增强肌醇磷脂周转的乙酰胆碱以及蛋白激酶C激活剂十四酰佛波醇乙酸酯（TPA）增强。在2 mM葡萄糖存在的情况下，这些试剂均未引发胰岛素分泌。葡萄糖刺激的胰岛素分泌明显依赖于细胞外Ca2+的浓度：在新鲜分离的胰岛中，当Ca2+浓度等于或低于10 microM时，葡萄糖不会诱发胰岛素分泌。胰岛培养44小时后，Ca2+的阈值需求增加。在新鲜和培养的胰岛中，分泌增强剂的存在均使葡萄糖刺激的胰岛素分泌最大速率显著增加，并降低了对细胞外Ca2+的需求。因此，胰岛素释放的增强涉及B细胞对Ca2+敏感性的增加。
