慢性冷暴露过程中SD大鼠RBC抗氧化系统和膜行为的变化

CHANGES OF RBC PEROXIDATION-ANTIOXI- DATION AND MEMBRANE FLUIDITY IN RATS DURING COLD ACCLIMATION

本研究以SD大鼠为模型,对慢性冷暴露过程中RBC过氧化与抗氧化机制的变化及膜部分行为的改变进行了动态观察。结果表明:(1) 冷适应初期抗氧化机制相对不足,过氧化占主导地位,过氧化物的堆积有可能造成一定的损伤而减弱机体的抗寒能力,而进一步抗氧化能力的增强则可能是冷适应建立的重要机制之一。(2) RBC在冷适应过程中抗氧化系统加强,包括SOD活性的升高与GSHPx活性的增强。(3) 慢性冷暴露过程中,SD大鼠RBC膜发生一定的组成变化和功能调整,而膜流动性变化却不显著。本实验为冷适应过程中脂质过氧化物(LPO)的存在提供了有力依据,为冷适应机理的研究与耐寒能力的探讨,提供了一条新的途径。

The changes of erythrocyte membrane fluidity and peroxidation-antioxidation in rats during cold acclimation were studied. The ten groups of twelve rats were used. Seven groups of cold-acclimating （CA） rats were exposed at 3℃ for 1,2,3,4,6,10,12 weeks, three groups of warm-acclimating （WA） rats were kept at 20℃ for 1,5,10 weeks as control of short-term, middle-term and long-term CA rats. No difference was found between those three groups. The lipid peroxidation of RBC was determined by assaying MDA content of RBC membrane. The membrane integrate of RBC was understood by determining erythrocyte autoxidative susceptibility. The antioxidative system in RBC was observed by assaying SOD activity and GSHPx activity and GSH content. The membrane fluidity was estimated with fluorescent DPH probe. The composition of erythrocyte membrane was showed by fluorescence intensity of ANS. The result showed an enhanced lipid peroxidation due to a sharply increase in oxygen consumption and O2-· in early stage of cold acclimation, resulted in a damage in membrane integrate and in ability of thermogenesis and in the capacity of cold-resistant in rats. And then the elevated antioxidation induced removal of peroxides,and an enhanced capacity to cold-resistant, and cold acclimation in rats was built. During the rats acclimation to cold, there was unmarked change in RBC membrane fluidity, although an enhanced ANS fluorescent intensity was observed. It suggested a possible shift in composition, amount and function in proteins of membrane, without a marked change in composition of membrane lipid.