家兔主动脉血管平滑肌细胞内钙动员及小檗胺作用的共聚焦研究

观察小檗胺 (Ber) 对高钾除极，Bay K8644，5-羟色胺 (5-HT) 及咖啡因升高细胞内钙水平 (［Ca²⁺］_i) 的影响。以Fluo-3/AM负载家兔培养的主动脉平滑肌细胞 (VSMC)，共聚焦显微术测定［Ca²⁺］_i，结果以荧光强度(FI)表示. 结果：(1) 在细胞外钙为1.3 mmol·L^-1时, VSMC胞浆静息FI明显高于核区, 且不受Ber的影响. (2) Ber 10-100 μmol·L^-1预处理可抑制KCl 60 mmol·L^-1或Bay K8644 100 μmol·L^-1升高的［Ca²⁺］_i，抑制5- HT 1 μmol·L^-1升高［Ca²⁺］_i的持续相，但不影响［Ca²⁺］_i的一过性升高。维拉帕米10 μmol·L^-1具有相似作用. (3) 在无钙Hanks液中，Ber预处理对咖啡因100 mmol·L^-1升高的［Ca²⁺］_i无明显抑制作用。结果表明，Ber可阻断外钙内流，但不抑制内钙释放，这可能与Ber阻断电压依赖性钙通道和受体依赖性钙通道的作用有关.

A confocal study of intracellular calcium mobilization and the effect of berbamine in cultured vascular smooth muscle cells from rabbit aorta

The aim of present paper is to investigate the effects of berbamine (Ber) on cytosolic free calcium concentration (［Ca²⁺］_i) elevated by high K⁺ depolarization, serotonin, and caffeine. Cultured vascular smooth muscle cell (VSMC) of rabbits was loaded with Fluo 3-AM, and ［Ca²⁺］_i was measured in fluorescent intensity (FI) by confocal microscopy. The results showed that (1) in the presence of extracellular Ca²⁺ 1.3 mmol·L^-1, the resting level of FI of ［Ca²⁺］_i in cytoplasm was much higher than that in nucleus of VSMC and not affected by pretreatment with Ber. (2) Pretreatment of VSMC with Ber 10-30 μmol·L^-1, KCl 60 mmol·L^-1 or Bay K8644 100 μmol·L^-1 induced ［Ca²⁺］_i elevation was inhibited (P<0.01). The sustained phase of ［Ca²⁺］_i elevation by serotonin 1 μmol·L^-1 was also reduced (P<0.01), while Ber did not work on the transient increase (P>0.05). The similar effects of Ber were also observed with verapamil 10 μmol·L^-1. (3) In D-Hanks solution, ［Ca²⁺］_i mobilization by caffeine 100 mmol·L^-1 was not suppressed (P>0.05) by Ber pretreatment. The present data suggested that Ber could block the Ca²⁺ influx probably due to both voltage-dependent Ca²⁺ channels and receptor-operated Ca²⁺ channels, but without the inhibitory effect on Ca²⁺ release.