Kanmura Y, Missiaen L, Casteels R
Department of Anesthesiology and Critical Care Medicine, Kagoshima University School of Medicine, Japan.
Anesth Analg. 1996 Nov;83(5):1105-9. doi: 10.1097/00000539-199611000-00036.
To investigate the effects of ketamine on Ca2+ movement to and from intracellular Ca2+ stores and across plasma membranes, 45Ca2+ fluxes were studied in permeabilized and intact A7r5 smooth muscle cells, an established cell line derived from embryonic rat aorta. Monolayers of A7r5 cells were loaded with 45Ca2+, and the radioactivity in the collected medium and the residual activity were measured by liquid scintillation counting. Ketamine had no effect on 45Ca2+ uptake and passive leak of the nonmitochondrial Ca2+ pool in permeabilized A7r5 cells. Ketamine 1 mM had no inhibitory effect on the inositol 1,4,5-trisphosphate (InsP3, 1 microM)-induced Ca2+ release from the intracellular stores. In intact A7r5 cells, ketamine did not alter the Ca2+ extrusion from these cells under resting conditions. Addition of 10 nM vasopressin resulted in a transient Ca2+ release from the intracellular stores. Ketamine inhibited this vasopressin-induced Ca2+ release, but did not enhance Ca2+ extrusion through the plasma membrane in the period after the vasopressin effect. These results indicate that ketamine inhibits agonist-induced Ca2+ release from intracellular stores, but has no effect on Ca(2+)-uptake into intracellular stores or on Ca2+ extrusion through the plasma membrane in A7r5 smooth muscle cells.
为了研究氯胺酮对细胞内钙库与细胞外之间以及跨质膜的Ca2+转运的影响，我们在经通透处理的和完整的A7r5平滑肌细胞（一种源自胚胎大鼠主动脉的成熟细胞系）中研究了45Ca2+通量。将A7r5细胞单层用45Ca2+加载，通过液体闪烁计数法测量收集培养基中的放射性和残留活性。氯胺酮对经通透处理的A7r5细胞中非线粒体钙库的45Ca2+摄取和被动渗漏没有影响。1 mM氯胺酮对肌醇1,4,5-三磷酸（InsP3，1 microM）诱导的细胞内钙库Ca2+释放没有抑制作用。在完整的A7r5细胞中，氯胺酮在静息条件下不会改变这些细胞的Ca2+外流。添加10 nM血管加压素会导致细胞内钙库的短暂Ca2+释放。氯胺酮抑制这种血管加压素诱导的Ca2+释放，但在血管加压素作用后的时间段内不会增强通过质膜的Ca2+外流。这些结果表明，氯胺酮抑制激动剂诱导的细胞内钙库Ca2+释放，但对A7r5平滑肌细胞中Ca2+摄入细胞内钙库或通过质膜的Ca2+外流没有影响。
