不同剂量维拉帕米和普奈洛尔钾停搏液对幼大鼠心功能影响

THE EFFECT OF DIFFERENT DOSE OF VERAPAMIL AND PROPRANOLOL IN KALIUM CARDIOPLEGIA ON THE FUNCTION OF IMMATURE RAT HEART

目的:观察含不同剂量维拉帕米和普奈洛尔的钾停搏液对未成年缺血心脏保护效应并与高钾停搏液比较,探讨适宜剂量。方法:幼大鼠离体心脏Langendorff法灌流,分6组(n=8):正常组(CON)连续灌流170 min;缺血-复灌组(I-R)灌流(稳定)20 min,无糖不充氧台氏液灌3 min停灌27 min连续3阵(缺血90 min),恢复正常灌流(复灌)60 min;高钾停搏液(ST)和低(L)、中(M)、高(H)剂量"钾维普"保护组缺血期每阵3 min灌注用不含(ST)和含维拉帕米、普奈洛尔(×10-7mol.L-1)分别为2.0、0.34(L),6.8、1.1(M),20、3.4(H)的ST.Thomas II号停搏液。实验过程实时动态检测心肌张力、心率、收缩力、最大收缩和舒张速度、冠脉流量、复搏时间评价心功能。结果:CON组灌流150 min心脏张力稳定,心功能降低;与CON组相比,I-R组缺血40 min后心脏挛缩,复灌后张力高,心搏功能丧失;ST组缺血60 min心肌张力升高,复灌后心功能减弱。与ST组相比,L、M、H"钾维普"呈剂量依赖性降低缺血心肌张力,复灌后心搏强;H组复搏延迟。与CON组相比,L组缺血60 min心脏张力升高,复灌后心搏弱;H组缺血40 min心脏张力低,但复灌后心搏弱;M组缺血90 min心脏张力稳定,复灌后心功能好,心搏幅度超过稳定值。结论:含维拉帕米6.8×10-7mol.L-1、普奈洛尔1.1×10-7mol.L-1的钾停搏液保护常温缺血90 min幼大鼠心脏效果最佳。

Aim： To explore the appropriate dose of the verapamil and propranolol in kalium cardiaplegia （KVP） by observation of the effect on the function of ischemic immature rat heart and compared with ST.Thomas II cardiaplegia.Methods： 48 isolated hearts from Sprague-Dawley rats of 60--80g body weight, 22±2 days, male or female are perfused by Langendorff method for 20 min, and assigned to 1 of the following 6 groups（ n = 8） ： control（CON）, continuously perfused for 150 min. Ischemia/reperfusion （I/R）, perfused with Locke＇ s solution without glucose and oxygen equilibration for 3 min then no perfusion 27 min, repeated 3 cycles （ischemia for 90 min）, followed by reperfusion for 60 min. Ischemia protected with ST. Thomas II cardioplegia（ST）, each 3 min perfusion with ST. Thomas II cardioplegia during ischemia. Ischemia protected with three dose KVP cardioplegia（L, M, and H）, perfused with ST. Thomas II cardioplegia containing verapamil and propranolol（×10^-7mol·L^-1 ）respectively 2.0,0.34（L）, 6.8, 1.1 （M）, 20,3.4（H） during each 3 min perfusion of ischemia. Heart rate（min^-1）, tension（g）, contraction force（g）, peak systolic velocity （g.ffl）, peak diastole velocity （g·s^-1 ）, coronary flow （ml·min^-1 ）, re-beat time （s） were monitored during the ischemia/ reperfusion.Results： Compared to CON group, heart tension was rose when ischemia for 40 min and kept higher and conld not rebeat after reperfusion in I/R group, In ST group, heart tension was rose after ischemia for 60 min and could re-beat but the pulse was weaker. Compared with ST group, KVP decreased the ischemic cardiac tension in dose dependently and the re-beat was stronger in L, M, and H groups. While compared with CON group, in L group, heart tension was rose when ischemia for 60 min and the re-beat was weaker. In H group, the heart tension was maintained lower when ischemia for 40 min and the re-beat was delay and weaker. Only in M group, heart tension was maintained stable during ischemia for 90 min and re-beat was stronger after reperfusion. Conclusion： Kalium eardiaplegia containing verapamil 6.8×10^-7mol·L^-1 and propranolol 1.1×10^-7mol·L^-1 has the best effect to protect the immature heart from ischemic injury.