Harty R F, Maico D G, McGuigan J E
Gastroenterology. 1981 Mar;80(3):491-7.
The role of calcium in gastrin release was investigated using rat antral organ culture. During the initial 4-h culture interval, in the absence of calcium in the culture medium, gastrin release was not different from that observed with 0.5, 1, and 2 mM calcium. However, after 6 h of culture, gastrin release with 0.5, 1, and 2 mM calcium was significantly greater than that with antral explants cultured in calcium-free media. In the presence of 1 mM calcium in the culture medium gastrin release was stimulated by dibutyryl cyclic AMP, whereas with calcium-free culture medium dibutyryl cyclic AMP was ineffective in stimulating gastrin release. Effects of ionophore A23187 on gastrin release were examined in experiments with culture medium containing no added calcium and with 2 mM calcium. The dose-response to ionophore A23187 (1.2--10 microgram/ml) with 2 mM calcium demonstrated progressive increases in culture media gastrin at 30, 60, and 120 min of culture. Maximal gastrin release occurred with 10 microgram/ml ionophore at each culture interval. Gastrin releases was not stimulated by increasing doses of ionophore when added to calcium-free organ culture media. Results of these experiments suggest that calcium is important in regulation of antral gastrin release and that dibutyryl cyclic AMP-stimulated release of antral gastrin is, at least in part, calcium-dependent. Stimulation of gastrin secretion by ionophore A23187 (in the presence of calcium) further supports the role of calcium in antral gastrin release and suggests that transport of calcium across cellular membranes is important in the coupling of secretory events in the gastrin cell.
采用大鼠胃窦器官培养法研究了钙在胃泌素释放中的作用。在最初4小时的培养期间，培养基中无钙时，胃泌素的释放与在含0.5、1和2 mM钙的培养基中观察到的情况无差异。然而，培养6小时后，含0.5、1和2 mM钙时胃泌素的释放显著高于在无钙培养基中培养的胃窦外植体。培养基中存在1 mM钙时，二丁酰环磷腺苷可刺激胃泌素释放，而在无钙培养基中，二丁酰环磷腺苷刺激胃泌素释放无效。在无添加钙的培养基和含2 mM钙的培养基的实验中，检测了离子载体A23187对胃泌素释放的影响。在含2 mM钙的情况下，对离子载体A23187（1.2 - 10微克/毫升）的剂量反应表明，在培养30、60和120分钟时，培养基中的胃泌素逐渐增加。在每个培养时间段，10微克/毫升离子载体时胃泌素释放达到最大。当添加到无钙器官培养基中时，增加剂量的离子载体不会刺激胃泌素释放。这些实验结果表明，钙在胃窦胃泌素释放的调节中很重要，并且二丁酰环磷腺苷刺激的胃窦胃泌素释放至少部分依赖于钙。离子载体A23187（在有钙的情况下）刺激胃泌素分泌进一步支持了钙在胃窦胃泌素释放中的作用，并表明钙跨细胞膜的转运在胃泌素细胞分泌事件的偶联中很重要。
