摘要
目的探讨+GZ负荷致大鼠膈肌收缩性能下降的原因。方法观察+GZ负荷后大鼠膈肌ATP酶活性的变化。将20只成年雄性SD大鼠随机分为对照组和+GZ负荷组(+GZ负荷量为:+4GZ始,每上升+1GZ持续3min,至+10GZ止,总负荷时间为21min)。所有动物均猛击头部后迅速剖开胸腹,取右半侧膈肌制成肌肉卷并即刻浸入液氮中冷冻。将冰冻肌肉条切成10μm厚切片,以钙钴法进行ATP酶染色,对染色切片进行图像分析,测定Ⅰ型和Ⅱ型纤维的面积及ATP酶光密度。结果两组动物在膈肌纤维组成上没有显著性差异(P>0.05),而+GZ负荷后各型纤维的ATP酶活性均有下降(P<0.05),尤以Ⅰ型纤维为著(P<0.01)。结论急性+GZ负荷条件下,大鼠膈肌肌球蛋白ATP酶活性下降是膈肌收缩性能改变的原因之一。
Objective To investigate the reason of diaphragm contractility decrease after sustained +G Z exposure in rats. Methods Twenty male adult sprague Dawley rats were randomly devided into two groups: +G Z group and control group. Rats of +G Z group underwent sustained +G Z exposure in animal centrifuge from +4 G Z up to +10 G Z for 21 min, while those of control group did not undergo +G Z exposure but fixed in the same fixture. After G Z exposure, the rat was fallen unconcious by a sudden hit on the head, and the right hemidiaphram was taken out frozened and sectioned. The sections were stained hy calcium cobalt method. The area and optical density of myosin ATPase of type Ⅰ and type Ⅱ fiber were measured with image analysis equipment. Results The difference of type Ⅰand type Ⅱ fiber proportion between two groups was nonsignificant ( P >0.05), while optical density of myosin ATPase in rats of +G Z group was significant lower than that in controls ( P <0.01), especially type Ⅰ fiber ( P <0.01). Conclusion It was suggested that the alteration of diaphragm contratibility following sustain +G Z exposure was mainly due to the lowering of myosin ATPase activity of diaphragm in rats.
出处
《中华航空航天医学杂志》
CSCD
1997年第3期176-178,共3页
Chinese Journal of Aerospace Medicine