The norepinephrine‐sensitive Ca2+ ‐storage site differs from the caffeine‐sensitive site in vascular smooth muscle of the rat aorta

[摘要]

Using microfluorometry of quin 2, a Ca²⁺-sensitive dye, we characterized the release and uptake of Ca²⁺ by the norepinephrine-sensitive Ca²⁺-storage site and the caffeine-sensitive one. The norepinephrine-sensitive Ca²⁺-storage site was readily depleted in Ca²⁺-free medium and almost completely replenished by loading with 1.0 mM Ca²⁺ solution for 3 min, whereas the caffeine-sensitive site was scarcely affected. Furthermore, norepinephrine has little effect on the caffeine-sensitive Ca²⁺-storage site in Ca²⁺-free medium, and vice versa. We conclude that the location and mechanisms of release and uptake of Ca²⁺ of these two Ca²⁺-storage sites differ in the case of rat aortic vascular smooth muscle cells in primary culture.

[学科分类] 生物化学/生物物理

[关键词] Ca2+ store;Norepinephrine;Caffeine;Quin 2;(Vascular smooth muscle cell;Rat aorta);[Ca2+]i;intracellular free calcium concentration;PSS;physiological saline solution;VSMCs;vascular smooth muscle cells;NE;norepinephrine