Dahl G, Henquin J C
Cell Tissue Res. 1978 Dec 12;194(3):387-98. doi: 10.1007/BF00236160.
Exposure of isolated pancreatic islets (mouse or rat) to low temperature (2 degrees C) evoked a threefold increase in insulin release irrespective of the glucose concentration in the incobation medium. Cold-induced release was transient and rewarming to 37 degrees C restored the sensitivity of B-cells to gluocose stimulation. In islets cooled to 2 degrees C, exocytotic profiles could easily be detected both by thin-section and freeze-fracture electron microscopy. As revealed by the freeze-fracture technique, the number of exocytotic profiles per membrane area was increased three- to fourfold as compared to islet cells incubated at 20 degrees C. This was paralleled by intracellular fusion of secretory vesicles. Cold-induced insulin release was not affected by theophylline, cytochalasin B, omission of extracellular Ca++ or D600. Replacement of extracellular Na+ with choline or sucrose suppressed the increase in insulin release and in frequency of exocytotic profiles recorded after exposure to 2 degrees C. It is suggested that a redistribution of Ca++ from intracellular stores, possibly mediated by an increase in intracellular Na+ triggers exocytosis of insulin granules upon exposure to cold.
将分离的胰岛（小鼠或大鼠）暴露于低温（2℃）会使胰岛素释放增加三倍，这与孵育培养基中的葡萄糖浓度无关。冷诱导释放是短暂的，将温度重新升至37℃可恢复β细胞对葡萄糖刺激的敏感性。在冷却至2℃的胰岛中，通过超薄切片和冷冻蚀刻电子显微镜都能很容易地检测到胞吐现象。冷冻蚀刻技术显示，与在20℃孵育的胰岛细胞相比，每单位膜面积的胞吐现象数量增加了三到四倍。这与分泌小泡的细胞内融合同时发生。冷诱导的胰岛素释放不受茶碱、细胞松弛素B、细胞外Ca++缺失或D600的影响。用胆碱或蔗糖替代细胞外Na+可抑制暴露于2℃后记录到的胰岛素释放增加和胞吐现象频率增加。提示细胞内储存的Ca++重新分布，可能由细胞内Na+增加介导，在暴露于寒冷时触发胰岛素颗粒的胞吐作用。
