高温、噪声及其复合因素对大鼠心肌线粒体三磷酸腺苷酶活性的影响

Effect of heat,noise and their combination on ATPase activities of myocardial mitochondria in rats

为了观察高温、噪声及其复合作用对大鼠心肌线粒体三磷酸腺苷酶（ATPase）活性的影响，笔者对80只大鼠分别进行高温（40℃，相对湿度82％）、噪声（115dB）及高温与噪声复合暴露。结果对照组、高温组、噪声组及其复合因素组心肌线粒体Ca2+－Ma2+－ATPase活性分别为10．57±6．13、16．64±1.61、12.66±1.82及14，35±1.97μmolPi·（mgProt）－1．h－1。高温组、复合因素组明显高于对照组（P＜0.01或0．05）；心肌线粒体Na+－K+－ATPase活性分别为4．46±2．06、8．48±3．54、764±2.16及6.09±2．13μmolPi·（mgprot）-1·h－1。高温组、噪声组反复合因素组均明显高于对照组（P＜0．01或0．05）。ATPase活性升高加速了三磷酸腺苷（ATP）的分解。ATP的过度消耗可导致心肌线粒体能量代谢障碍，聚Ca2+受阻，引起胞浆内Ca2+稳态失调，胞浆内Ca2+超载，造成心肌细胞中毒损伤。

ATPase activities of myocardial mitochondria were determined in rats after exposure to heat (40℃,relative humidity 82 %),noise (115 dB) and their combination for 1 h, The results: ① Ca2+-Mg2+-ATPase activity in control group, heat group, noise group and combined group were 10. 57±6.13, 16. 64±1. 61, 12.66±1. 82 and 14. 35±1. 97 μmol Pi· (mg prot)-1·h-1 respectively. Those of heat group and combined group increased significantly, compared with that of control (P＜0.01 or Pr＜0.05). ②Na+-K+-ATPase activity were 4. 46 ± 2. 06, 8. 48±3. 54, 7. 64±2. 16 and 6. 09±2. 13 μmol Pi·(mg prot) -1·h-1 respectively. Those of heat group,noise group and combined group all increased obvi-ously, compared with that of control (P＜0.01 or P＜0. 05). Increase of ATPase activities after heat and noise exposure in rats might be caused by excitement of sympathetic nerve and raise of thyroxines. The higher ATPase activities are, the more catabolism of ATP will be. ATP exhaustion will disturb metabolism of energy of myocardial mitochondria and Ca2+ overload will damage myocardial cells.