不同负荷运动对大鼠血浆和心肌细胞内ET及心肌细胞膜ETR的影响

INFLUENCE OF EXERCISE ON BOTH ET LEVELS IN PLASMA AND MYOCARDIAL CELLS AND ET RECEPTOR ON THE MYOCARDIAL CELLS MEMBRANE IN RATS

目的:探讨不同运动负荷的游泳训练对SD大鼠血浆和心肌细胞中内皮素(ET)含量及心肌细胞膜上内皮素受体(ETR)活性的影响。方法:雄性SD大鼠分为5组,即A组(安静对照组)、B组(游泳45min组)、C组(游泳90min组)、D组(游泳150min组)、E组(急性力竭组),每组9只进行8周的游泳训练,用放射免疫法测定大鼠ET及ETR。结果:90min组大鼠血浆和心肌细胞中ET比对照组有明显降低(P<0.01),且可下调ETR的数量和亲和力(P<0.01)。150min组大鼠心肌细胞膜上ETR的解离常数Kd值明显低于对照组(P<0.01)。结论:中等负荷的运动可明显改善心血管系统的功能,而负荷较大的运动对心血管系统功能的改善不利。

The purpose of the present study is to discuss the influence of different exercise load on the concentration of ET in plasma and myocardial cells,and the activity of ETR on myocardial cell＇s membrane ira-ors. Methods： 45 male SD rats were divided into the following 5 groups randomly： Group A（control group） ; Group B（45 min swim group） ; Group C（90 min swim group） ; Coup D（150 min swim group） ; Group E（acute exhaust group）. After having been trained for 8 weeks, the levels of ET and activity of ETR were measured by RIA. Results： The concentrations of ET in plasma and myocardial cells of 90 min swim group were decreased significantly （P 〈 0.01 ）and 90 min swim could reduce the activity of ETR（ P 〈 0.01 ）. The activity of ETR was elevated significantly in 150 min swim group（P〈 0.01）. Conclusion： Moderate exercise loads can significantly ameliorate the cardiovascular function, and high exercise loads is harmful to myocardial cells.