C-型钠尿肽对兔离体右心房功能的影响

Effects of C-Type Natriuretic Peptide on Isolated Right Atrial Function in Rabbits

目的:探讨C-型钠尿肽(CNP)对兔离体右心房动力和内分泌功能的影响。方法:选用雄性新西兰兔47只。随机分七组:为观察CNP的浓度依赖性效应,兔右心房分别用CNP10-8mol/L(10-8mol/L组,n=6)、10-7mol/L(10-7mol/L组,n=6)、10-6mol/L(10-6mol/L组,n=6)处理30min;心房灌流对照组(n=6),心房灌流实验组(n=8);自律心房对照组(n=6),自律心房实验组(n=9)。采用兔离体搏动右心房灌流模型和放射免疫分析方法,观察CNP对右心房每搏输出量、每搏压和心房钠尿肽(ANP)分泌的效应;采用兔离体自律心房模型,观察CNP对窦性心律的影响。结果:CNP(10-8mol/L,10-7mol/L,10-6mol/L)三种浓度对右心房的每搏输出量和ANP分泌均有抑制作用,并且抑制效应呈浓度依赖性地增强(P<0.05或<0.01)。心房灌流对照组和自律心房对照组后期与前期比较,右心房每搏输出量、每搏压、ANP分泌和心率均处于稳定状态,差异无统计学意义(P>0.05)。心房灌流实验组和自律心房实验组CNP处理后与CNP处理前比较,右心房每搏输出量、每搏压和ANP分泌明显降低(P<0.01),但心率增加明显(P<0.01),差异有统计学意义。结论:CNP可抑制右心房的收缩和ANP分泌功能,增加窦性心律。

Objective： To define the effects of C-type natriuretic peptide （CNP） in regulation of isolated right atrial dynamics,secretion and heart rate in rabbits. Methods ： A total of 47 male rabbits were randomly divided into 7 groups ： ①ln order to observe the effects of CNP dose dependence,rabbit right atria were treated as CNP 10-s mol/L group, n= 6, CNP10 7 mol/L group, n = 6, and CNP10^-6 mol/L group, n = 6, for 30 minutes respectively ; ②Control group of perfused atria, n = 6, and Experimental group of perfused atria, n = 8 ; ③Control group of autonomic atria, n = 6, and Experimental group of autonomic atria, n = 9. Experiments were performed in perfused beating rabbit＇ s right atria using radioimmunoassay to determine the effects of CNP on the stroke volume, pressure and atrial natriuretic peptide （ANP） secretion. Experiments were also conducted in isolated autonomic beating rabbit＇s right atria to observe the effect of CNP on the heart rate. Results： CNP groups（ lO-S mol/L, 10^-7 mol/L and 10^-6 mol/L）suppressed the right atrial stroke volume and ANP secretion in a dose dependent model（ P 〈 0. 05 or 0. 01 ）. In both Control group of perfused atria and Control group of autonomic atria, the right atrial stroke volume,pressure, ANP secretion and heart rate were stable during the experimental period. In Experimental group of perfused atria and Experimental group of autonomic atria, CNP（ 10^-7 tooL/L） significantly decreased the right atrial stroke volume, pressure and ANP secretion（ P 〈 0. 01 ）, but increased the heart rate （P 〈 0. 01 ）. Conclusion： CNP could decrease the dynamics and ANP secretion, and meanwhile,increase the heart rate in isolated right atria in rabbits.