Ishii N, Simpson A W, Ashley C C
University Laboratory of Physiology, Oxford, U.K.
Biochem Biophys Res Commun. 1988 Jun 16;153(2):683-9. doi: 10.1016/s0006-291x(88)81149-5.
Intracellular free calcium concentration [( Ca2+]1) was measured in suspensions of fura-2 loaded smooth-muscle cells isolated from the anterior byssus retractor muscle of Mytilus edulis. Successive application of 5mM carbachol (CCh) and 100mM KCl to the cells transiently elevated [Ca2+]1 from the resting value of 124 +/- 4.5nM (mean +/- S.E., n = 14) to 295 +/- 15.3 and 383 +/- 20.5 nM, respectively. The response to CCh was concentration-dependent with an ED50 of 10(-5) M. Under the microscope, 67 +/- 3.0 and 83 +/- 1.3 % of fura-2 loaded cells contracted on the addition of 5mM CCh and 100mM KCl, respectively. In Ca2+ -free sea water, the CCh induced change in [Ca2+]1 was partially suppressed whereas that induced by KCl was completely abolished, suggesting an agonist-evoked release of stored Ca2+.
在从贻贝前足缩肌分离出的、用fura - 2负载的平滑肌细胞悬液中测量细胞内游离钙浓度[(Ca2 +]i)。向细胞中依次施加5mM卡巴胆碱(CCh)和100mM KCl,使[Ca2 +]i从124±4.5nM(平均值±标准误,n = 14)的静息值分别短暂升高至295±15.3和383±20.5 nM。对CCh的反应呈浓度依赖性,ED50为10(-5)M。在显微镜下,分别添加5mM CCh和100mM KCl时,67±3.0%和83±1.3%的用fura - 2负载的细胞发生收缩。在无钙海水中,CCh诱导的[Ca2 +]i变化被部分抑制,而KCl诱导的变化则完全消除,提示激动剂诱发储存钙的释放。