不同温度“钾维普”停搏对幼大鼠心功能的影响

Study on the effect of cardioplegia incluced by kalium-verapamil-propranolol in different temperatures on the function of immature rat heart

目的:探讨未成熟缺血心脏"钾维普"停搏保护的适宜温度。方法:离体幼大鼠心脏Langendorff法灌流,分5组(n=6～8)。对照组:36℃正常灌流170 min;36℃(常温)组:正常灌流20 min,灌"钾维普"停搏液(KVP)3 min停灌87 min(常温停搏90 min),恢复正常灌流(复灌)60 min;32、28、24℃(低温)组:正常灌流15 min,5 min内分别降温至32、28、24℃,灌KVP3 min停灌87 min(低温停搏90 min),复灌60 min。实验过程实时监测心率(b/min)、心肌张力(g)、收缩力(g)、最大收缩速度(dT/dtmax)、最大舒张速度(-dT/dtmax)及冠脉流量(drop/min)反映心功能。结果:与对照组相比,各组KVP停搏50 min后心脏张力均增高;与低温停搏相比,常温停搏的心脏不良挛缩迟缓、复灌后心脏张力、心率、收缩力、冠脉流量恢复好(P<0.05)。结论:未成熟缺血心脏常温"钾维普"停搏保护效果优于低温停搏。

Objective： To explore the appropriate temperature of the kalium-vempamil-propranolol （KVP） cardioplegia by observation of the effect on the function of the immature rat heart. Methods： Isolated hearts from immature rats were perfused by Langendortt method, and assigned to 1 of the following 5 groups（ n = 6 - 8） ： control, continuously peffused for 170 min at 36℃, normal temperature, normal perfused for 20 min, changed to perfuse with KVP for 3 min then no perfusion 87 min（ischemia 90 min）,foUowed by 60 rain reperfusion. 3 groups of low temperature, peffused for 15 min, cool down to 32℃, .28℃ and 24℃ especially in 5 min, and at 20th min. heart rate（b/min）, tension （g）, contraction force（g）, peak systolic velecity（dT/dtmax）, peak diastole velocity（dT/dtmax）, coronary llow（Drop/min）were monitored during the whole perfusion. Results： Compared to control group, the heart tension increased after 50 rain KVP ischemia. The protection of KVP in normal tempemture（36℃） was better than lower tempemture（32℃,28℃,24℃） such as reducing bad contraction, keeping normal myocardium tensian,recovering heart rate, reco-cering the ruction of contration force and protecting the coronary flow. Conclusion： The KVP cardioplegia in normal temperature has the better effect than that in hypothermia to protect the immature heart.