【摘要】 目的:观察前胡丙素(Prc-C)对自发性高血压大鼠(SHR)及肾性高血压大鼠(RHR)心肌细胞膜Na+,K+-ATP酶及线粒体Na+,K+-ATP酶、Ca2+-ATP酶及Mg2+-ATP酶活性及酶促动力学参数的影响。方法:采用光电比色法测定ATP酶活性,并通过测定不同ATP浓度时的ATP酶活力,根据Lineweaven-Burk公式作图并经加权线性回归法拟合直线,进而推算酶促反应动力学参数Km及Vmax。结果:SHR及RHR心肌Na+,K+-ATP酶及Ca2+-ATP酶活性下降,最大反应速度(Vmax)降低。酶促动力学研究发现ATP酶反应速率常数(Km)在SHR增大,在RHR无显著性改变;Pra-C长期给药可加强酶活力,升高酶Vmax而不影响Km。结论:SHR及RHR心肌ATP酶变化存在差异,RHR心肌ATP酶活力的下降主要因为心肌组织ATP酶含量减少,而非酶与底物ATP的亲和力变化;而SHR心肌ATP酶活力的下降由于心肌组织ATP酶含量减少及酶与底物ATP的亲和力下降两方面原因。前胡丙素长期用药可增加单位重量心肌组织ATP酶含量,但不影响酶与底物ATP的亲和力。更多还原

【Abstract】 AIM: To study the effects of prearuptorin C (Pra-C) on myocardial sarcolemma Na~+, K~+-ATPase activity, myocardial mitochondria Na~+, K~+-ATPase, Ca~ 2+ -ATPase, Mg~ 2+ -ATPase activities and apperent Km and Vmax in spontaneously hypertensive (SHR) and renovascular hypertensive rats (RHR). METHODS: ATPase activity was measured with colourmetric method. Apparent Km and Vmax of both Na~+, K~+-ATPase in myocardial sarcolemma and Ca~ 2+ -ATPase in myocardial mitochondria were calculated according to Lineweaven-Burk double-reciprocal plot method with liner regression. RESULTS: The Vmax of both Na~+, K~+-ATPase in myocardial sarcolemma and Ca~ 2+ -ATPase in myocardial mitochondria were lower in SHR untreated group than that in SD control rats, while Km was higher than that in SD control rats. In RHRs untreated group, only Vmax was decreased, while the Km had no statistically change. Pra-C prevented the reduction of ATPase in amount, but not affected their intrinsic characteristics. CONCLUSIONS: The results suggest that both amounts and affinities to ATP of Na~+, K~+-ATPase and Ca~ 2+ -ATPase were decreased in SHRs, but in RHRs, only amounts of ATPase was decreased, while their affinities to ATP were unchanged. Treatment with Pra-C prevents the decrease in amount of ATPase.更多还原