地尔硫䓬对人胎盘静脉中5-羟色胺和钾诱导的收缩的干扰作用。

Interference of diltiazem with serotonin- and potassium-induced contractions in human placental veins.

Marín J, Fernandez-Alfonso M S, Reviriego J, Guerra P

Departamento de Farmacología y Terapéutica, Facultad de Medicina, Universidad Autónoma de Madrid, Spain.

Gen Pharmacol. 1990;21(5):715-8. doi: 10.1016/0306-3623(90)91023-k.

Abstract

In segments of human placental veins precontracted with K+ (25, 40 or 75 mM), diltiazem produced concentration-dependent relaxations with similar EC50 values. 2. Diltiazem (20 min preincubations) also caused concentration-dependent inhibition of the contractions induced by K+ (40 or 75 mM) and 5-HT (serotonin, 3 x 10(-7) M). IC50 values were similar, in both cases. 3. The time-course of the vasocontractions induced by 75 mM K+ and 3 x 10(-7) M 5-HT in the absence and in the presence of diltiazem were different. The contractions caused by K+ were sustained and transient those elicited by 5-HT. 4. These data suggest that (1) this vasculature is sensitive to diltiazem, and (2) the Ca influx through voltage-operated Ca channels (activated by K+) and through receptor-operated Ca channels (activated by 5-HT) is very similar.

摘要

在预先用钾离子（25、40或75毫摩尔）预收缩的人胎盘静脉段中，地尔硫卓产生浓度依赖性舒张，其半数有效浓度（EC50）值相似。2. 地尔硫卓（预孵育20分钟）还引起对由钾离子（40或75毫摩尔）和5-羟色胺（血清素，3×10⁻⁷摩尔）诱导的收缩的浓度依赖性抑制。在两种情况下，半数抑制浓度（IC50）值相似。3. 在不存在和存在地尔硫卓的情况下，由75毫摩尔钾离子和3×10⁻⁷摩尔5-羟色胺诱导的血管收缩的时间进程不同。由钾离子引起的收缩是持续的，而由5-羟色胺引起的收缩是短暂的。4. 这些数据表明：（1）这种血管系统对地尔硫卓敏感；（2）通过电压门控钙通道（由钾离子激活）和通过受体门控钙通道（由5-羟色胺激活）的钙内流非常相似。