烧伤对豚鼠离体灌流心脏收缩及舒张功能的影响

Effect of Burn Injury on the Contractile and Relaxation function of Isolated Perfusion Heart in Guinea-pigs

本文利用顺行洼离体灌流心脏模型,观测了豚鼠在35％体表Ⅲ°烧伤后1h、3h、8h及24h心脏收缩及舒张功能,心室肌细胞动作电位的各项参数和心肌氧耗量、葡萄糖消耗量的改变。结果表明:(1)烧伤豚鼠心脏的舒缩功能经历了一个正常—降低—渐恢复的时程变化。即烧伤后1h内心功能仍属正常,以后心脏舒缩功能逐渐降低,8h左右达最低,但在烧伤后24h,心功能已有部份恢复,提示烧伤动物的心脏存在自我修复机制;(2)心肌收缩性的降低与心肌氧耗量降低直接相关,而不是由于营养物的摄取减少;(3)在体情况下,烧伤对冠脉流量及心肌细胞电活动的影响因素较易被灌流液所清除,提示这些影响可能来自心外的神经及体液因素。

By mean of the isolated perfused working heart model, the changes of myocardial contractile and relaxation functions, ventricular cell action potentials, myocardial oxygen and glucose consumptions etc. were observed at 1st,3rd, 8th and 24th h after burn injury in the guinea-pigs inflictedly III degree burn injury on 35% TBA. The results indicate that. 1 ) The contractile and relaxation functions go through a time course of 'normal-decrease-recover', i.e. the cardiac functions show a normal level within 1 h after burn injury. Then they are depressed gradually,and to the lowest at 8th h or so, after burn injury. The cardiac functions recover partly at 24th h after burn injury. It suggests that there is a repaired mechanism by itself in heart of the burn animal; 2 ) The depression of myocardial contractile and relaxation functions are related with depression of the oxygen consumption rather than reduce of intaking in nutrients; 3) the influencing factors of burn injury on the coronary flow and electrical activity of myocardial cells could be removed easily by the perfusate. It shows that these effects may be result from the extracardiac neurohumoral factors.