尾悬吊大鼠比目鱼肌肌钙蛋白I异构体的转化与睾丸萎缩  

Transition of Soleus Troponin I Isoforms and Atrophy of Testis in Tail-suspended Rats

作　　者：冯汉忠[1] 余志斌[1] 谢满江[1] 孙标[1] 宋华 张立藩[1] 

机构地区：[1]第四军医大学航空航天生理学教研室,西安710032

出　　处：《航天医学与医学工程》2001年第3期172-176,共5页Space Medicine & Medical Engineering

摘　　要：目的确定大鼠比目鱼肌肌钙蛋白I(TnI)发生转化的时间 ,并分析其与比目鱼肌萎缩时间过程间的相关关系 ;分析睾酮水平降低与抗重力肌萎缩速度之间的关系。方法将雄性大鼠分为 8组 ,悬吊时间分别为 3、4、5、7、1 4、2 1、2 8与 42d。测量雄性悬吊大鼠睾丸和比目鱼肌的湿重并计算相对重量 (湿重/体重 ) ,同时采用Westernblot对悬吊大鼠比目鱼肌TnI的表达水平进行观测。将雌性大鼠分为 3组 ,悬吊时间分别为 3、4与 5d ,测量其比目鱼肌的湿重并计算其相对重量。结果雄性悬吊大鼠的比目鱼肌湿重和相对重量在第 4天显著降低 ,1 4d萎缩程度最明显。悬吊大鼠睾丸的湿重在第 5天出现显著萎缩 ,相对重量在第 4天发生了显著萎缩。雌性悬吊大鼠比目鱼肌的湿重与相对重量 4d时没有明显变化 ,在第 5天才显著降低。比目鱼肌TnI在悬吊 1 4d出现由ssTnI向fsTnI的转化。结论雄性悬吊大鼠抗重力肌 (比目鱼肌 )发生由ssTnI向fsTnI转化的时间为 1 4d ,这与抗重力肌发生显著萎缩的时间(4d)并不一致 ,提示TnI可能不是引起模拟失重后抗重力肌萎缩的随重力的降低而发生敏感变化的蛋白。同时 ,雌性大鼠抗重力肌发生显著萎缩的时间是 5d 。Objective To observe the transition time of soleus troponin I (TnI) isoforms and to elucidate the relationship between soleus TnI transition and atrophy; and to analyze the time course between testis atrophy and soleus atrophy. Method Eight groups of male rats were suspended for 3, 4, 5, 7, 14, 21, 28 and 42 d, respectively. Besides, three groups of female rats were suspended for 3, 4 and 5 d respectively. Wet and relative weights (wet weight / body weight) of testis and soleus were measured. The expression of TnI was observed by Western blot. Result The relative weight of soleus of tail suspended male rats decreased significantly after 4 d of suspension as compared with control. The degree of rats soleus atrophy in the first 14 d of suspension was greater than that after 14 d. The relative weight of testis showed the same change as that of soleus. There was no significant change in the relative weight of soleus in 4 d of tail suspended female rats. The significant decrease in the relative weight of tail suspended female rats began on the 5th day. The Western blot showed that the transition from slow skeletal TnI (ssTnI) to fast skeletal TnI (fsTnI) in the soleus occurred in 14 d of tail suspension. Conclusion The overt atrophy of tail suspended male rats occurs on the 4th day. The soleus TnI transition from ssTnI to fsTnI is on the 14th day. It is suggested that the TnI is not the sensitive protein to gravity. The overt atrophy of female tail suspended rats occurs at the 5th day. This indicated that the decrease in testosterone level may accelerate the atrophy of the soleus.

关 键 词：失重模拟 尾悬 肌钙蛋白 异构体 睾丸萎缩 

分 类 号：R852.22[医药卫生—航空、航天与航海医学] R697.22[医药卫生—临床医学]