Yasuda N, Sakai Y
Comp Biochem Physiol A Comp Physiol. 1984;78(1):35-41. doi: 10.1016/0300-9629(84)90088-4.
Effects of Sr2+ on smooth muscle activity and Ca2+ movement by plasma membrane (PM) were examined in preparations isolated from canine stomach to determine how Sr2+ modulates the contraction-relaxation cycle in smooth muscle. Sr2+ caused contraction in Ca2+-free solution. In the presence of Sr2+, KCl caused a response similar to that in normal Ringer's solution, this contraction was inhibited by both nitroprusside and verapamil. Sr2+ inhibited Ca2+ uptake by PM in the presence and absence of ATP. Release of Ca2+ from loaded PM vesicles was accelerated by Sr2+. Results suggest that Sr2+ could replace Ca2+ in Ca2+ binding sites in the cell.
通过从犬胃分离的制剂，研究了Sr2+对平滑肌活性和质膜（PM）Ca2+转运的影响，以确定Sr2+如何调节平滑肌的收缩-舒张周期。Sr2+在无Ca2+溶液中引起收缩。在存在Sr2+的情况下，KCl引起的反应与在正常林格氏液中相似，这种收缩被硝普钠和维拉帕米抑制。无论有无ATP，Sr2+均抑制PM对Ca2+的摄取。Sr2+加速了加载的PM囊泡中Ca2+的释放。结果表明，Sr2+可以取代细胞中Ca2+结合位点上的Ca2+。
