[Effect of antihypertensive factor on Ca2+ influx in arterial smooth muscle from normotensive and spontaneously hypertensive rats].
Aorta segments (A) and mesenteric arteries (MA) from stroke prone spontaneously hypertensive rats (SHRsp) and control Wistar Kyoto rats (WKY) were used in the present study to assess the effect of AHF on Ca2+ influx in vascular smooth muscle (VSM). The results indicated that Ca2+ influx in VSM of SHRsp was much higher than that of WKY rats (P less than 0.05). AHF at 10(-7), 10(-6) and 10(-5) g/ml can significantly inhibit Ca2+ influx in a dose-dependent manner in VSM of both A and MA (P less than 0.05 and less than 0.01). The suppression effect of AHF on Ca2+ influx and the concentration-dependent relationship were more obvious in MA than in A. The Ca2+ influx in VSM of WKY rats was unaffected by administration of AHF.