赛庚啶对离体犬心肌肌质网Ca2+,Mg2+—ATP酶活性和45Ca2+摄取功能的影响

当赛庚啶浓度在8×10^-6mol/L～2×10^-4mol/L之间时,该药对正常犬心肌肌质网Ca²⁺,Mg²⁺—ATP酶活性几乎没有影响,仅在10^-3mol/L时对该酶活性才有一定的抑制作用(抑制率为39.85%,P<0.01)。正常犬心肌肌质网的⁴⁵Ca²⁺摄取过程有明显的时间依赖性,至第30 min,其⁴⁵Ca²⁺摄取量可达312.79±22.25 nmol/mg protein.赛庚啶对心肌肌质网的~(45)Ca²⁺摄取有一定的抑制作用,其IC₅₀为1.94×10^-4mol/L。

EFFECT OF CYPROHEPTADINE ON Ca2+,Mg2+-ATPase ACTIVITIES AND 45Ca2+ UPTAKE FUNCTION IN CANINE MYOCARDIAL SARCOPLASMIC RETICULUM

The effects of cyproheptadine on Ca²⁺, Mg²⁺--ATPase activities and ⁴⁵Ca²⁺ uptake function in isolated canine myocardial sarcoplasmic reticulum were studied. Cyproheptadine at concentrations of 8×10^-6 mol/L～2×10^-4 mol/L showed hardly any influence on Ca²⁺ , Mg²⁺-- ATPase activities of the myocardial sarcoplasmic reticulum in canine, but inhibited the enzyme activities (rate of inhibition: 39.85%, P<0. 01) at the concentration of 10^-3 mol/L. The myocardial sarcoplasmic reticulum was shown to take up ⁴⁵Ca²⁺ significantly in a time-dependent manner and the ₄₅Ca²⁺ uptake was 312. 79±22.25 nmol/mg protein at 30 min. Cyproheptadine was found to inhibit the Ca²⁺ uptake of sarcoplasmic reticulum with an IC₅₀ of 1.94×10^-4 mol/L.