萘哌地尔衍生物(BWYJ)对血管平滑肌细胞游离钙浓度的影响

目的: 观察萘哌地尔衍生物(BWYJ) 对家兔血管平滑肌细胞游离钙浓度的影响, 对其血管活性进行机理探讨, 进一步明确其作用机制。方法: 采用钙荧光指示剂Fura-2 /AM 负载的培养家兔胸主动脉平滑肌细胞, 观察该药对NA 、5-HT 和高钾所致的Ca²⁺] _i 的升高的影响。结果: Fura-2 /AM 负载血管平滑肌细胞的实验中, 静息时各浓度的BWYJ 对Ca²⁺]_i 无明显影响, 但其对NA 和5-HT 所引起的血管平滑肌Ca²⁺] _i 增加均有明显的抑制作用, 而不影响高钾所致血管平滑肌Ca²⁺] _i 的增加。结论: BWYJ 通过阻断细胞膜上的α₁ 受体或5-HT₂A 受体,抑制这些受体中介的钙内流, 从而抑制细胞内Ca²⁺的释放, 使血管平滑肌Ca²⁺] _i 降低。

Effects of Naftopidil’ ramification-BWYJ on intracellularlar free Ca2+ in smooth cells

AIM: To observed the effects of BWYJ (a naftopidil ramification) on intracellularlar free Ca²⁺ (Ca²⁺]_i) in smooth cells (SMCs) in order to further explore its vasodilative mechanisms. METHODS: The Ca²⁺] _i was determined with the Fura-2 /AM loaded SMCs in aorta of rabbit, and the effects of BWYJ on the elevation induced by NA, and high potassium and 5-HT were observe. RESULTS: In the Fura-2 /AM loaded SMCs, BWYJ had no effect on the resting Ca²⁺] _i, but it reduced the increase of Ca²⁺] _i induced by NA and 5- HT, and there was no influence on the increase of Ca²⁺] _i induced by high potassium. CONCLUSION: The vasodilative mechanisms of BWYJ may be related to its inhibitive effects on the Ca²⁺-influx and Ca²⁺-release mediated by α₁- and 5-HT₂A receptors. It inhibits the release of intracellular calcium, and the result is it decrease the Ca²⁺] _i in SMCs.