模拟失重对乌龟心肌的影响

THE EFFECTS OF SIMULATED WEIGHTLESSNESS ON MYOCARDIUM OF TORTOISE

乌龟采用悬吊模拟失重，经悬吊21天后，乌龟心率加快，pH值下降；PC0O增加．Mb明显从362．7±37nmol／g下降到246．8±21．7nmol／g；MDA明显地从对照值32．2±2．7nmol／g增加到46．0±2．1nmol／g（P＜0．05）．心肌有严重损伤，肌丝断裂和线粒体空泡增多等．本研究结果提示，悬吊模拟失重对乌龟心肌有影响，乌龟能作为实验动物应用于空间生物学研究．

Weightlessness of tortoise was simulated by suspension experiment. Groups of tortoises were divided by suspension time. The first group is control group.The tortoises of second group were suspended for 21 days and the third group for 14 days (five animals each group). After suspension, heart rate, myoglobin (Mb)and ma1onidialdehyde (MDA) of myocardium were measured. Blood of tortoises were carried out blood gas analyses by ABL3 Acid-Base Laboratory (Radiometer Copenhagen). Changes of ultrastructurc of myocaxdium also were observed through electron microscope.The results showed that the body weight of tortoise decreased from 78.7±5.3 g to 76.9±5.3 g after 21 days of suspension while there was no change after 14 days of suspension. After 21 days of suspension, heart rate increased, blood pH decreased from 7.39±0.02 to 7.28±0.03, and blood PCO2 increased from 52.9±2.1 mmHg to 65.8±3.4mmHg (P <0.05). The results of electron microscope showed that there were severe damages of myocardium such as myofilaments rupture and vacuole of mitochondria.It was suggested that by means of simulation, effects of simulated weightlessness on myocardium of tortoise could be found and tortoise can be used as an experiment animal on field of space biology study.