Meats J E, Best L, Lynch A M, Tomlinson S
Department of Medicine, University of Manchester, UK.
Cell Calcium. 1989 Nov-Dec;10(8):535-41. doi: 10.1016/0143-4160(89)90015-8.
We have investigated the effects of glucose on cytosolic free calcium concentration in the insulin-secreting cell line HIT-T15. Addition of glucose (10 mM) caused a 20-75% increase in cytosolic [Ca2+] within 5 minutes compared to controls in the absence of glucose. A maximal increase in cytosolic [Ca2+] was obtained with 5 mM glucose. The magnitude of the response was markedly dependent upon the concentration of extracellular Ca2+, and the rise in cytosolic [Ca2+] was inhibited by verapamil. Cytosolic [Ca2+] was greatly increased by depolarization of the cells with KCl (50 mM), whereas carbamylcholine had no apparent effect. Glucose and KCl were also effective in stimulating insulin release from HIT cells, although carbamylcholine was again ineffective. The secretory response to glucose was also found to be directly related to the concentration of extracellular [Ca2+]. Glucose and KCl, but not carbamylcholine, were found to slightly enhance the production of [3H]-inositol trisphosphate in HIT cells pre-labelled with myo-[3H]-inositol, indicating a modest stimulation of inositol lipid hydrolysis.
我们研究了葡萄糖对胰岛素分泌细胞系HIT-T15胞质游离钙浓度的影响。与无葡萄糖的对照组相比，添加葡萄糖（10 mM）在5分钟内使胞质[Ca2+]增加了20 - 75%。5 mM葡萄糖可使胞质[Ca2+]达到最大增加。反应幅度明显依赖于细胞外Ca2+浓度，维拉帕米可抑制胞质[Ca2+]的升高。用氯化钾（50 mM）使细胞去极化可使胞质[Ca2+]大幅增加，而氨甲酰胆碱无明显作用。葡萄糖和氯化钾也能有效刺激HIT细胞释放胰岛素，尽管氨甲酰胆碱同样无效。还发现对葡萄糖的分泌反应与细胞外[Ca2+]浓度直接相关。在用肌醇-[3H]-肌醇预标记的HIT细胞中，发现葡萄糖和氯化钾而非氨甲酰胆碱能轻微增强[3H]-肌醇三磷酸的产生，表明对肌醇脂质水解有适度刺激。
