冷暴露大鼠红细胞膜及肝组织中某些酶的活性变化

STUDIES ON SOME ENZYME ACTIVITIES IN RAT ERYTHROCYTE MEMBRANE AND LIVER TISSUE DURING COLD EXPOSURE

本文对大鼠冷暴露的第1、2、3、4、6周时红细胞膜Na^+、K^+-ATPase、肝组织腺苷酸环化酶(Adenyl cyclase,AC)以及环腺苷酸磷酸二酯酶(cAMP phosphodiesterase,PDE)的活性变化进行了研究。结果表明,大鼠冷暴露第1周时,3种酶活性均增至最高水平;在第2至第6周时,酶活性呈下降趋势。大鼠在整个冷暴露期间,红细胞膜Na^+、K^+-ATPase活性都显著高于对照水平(P<0.05)。冷暴露第4周时,肝组织AC及PDE活性均降至对照水平(P>0.05)。研究表明,大鼠红细胞膜Na^+、K^+-ATPase在冷适应的建立和形成过程中起代谢调节作用。肝组织AC及PDE在冷应激阶段起代谢调节作用,而在冷适应阶段则不起作用。

The activities of the erythrocyte membrane Na^+, K^+-ATPase, adenyl cyclase (AC) and cAMP phosphodiesterase (PDE) in liver tissue were studied. The activities of these three enzymes were measured at the 1st, 2nd, 3rd, 4th, and 6th weeks during cold exposure. The results showed that the enzyme activities reached their peaks at the 1st week of cold exposure,but gradually declined during the 2nd to 6th weeks of cold exposure. The Na^+, K^+-ATPase activities in the experimental groups were obviously higher than that in the control groups at all measuring time (P<0.05). When the rats were exposed to cold for four weeks the activities of AC and PDE returned to control values (P>0.05). The data obtained suggested that erythrocyte membrane Na^+, K^+-ATPase in cold exposed rats plays the metabolic regulating role during cold adaptation process. The AC and PDE in liver tissue of the cold exposed rats were involved in the regulation of metabolism during the cold stress phase, but had no effect on cold adaptation phase.