[The adaptive changes in vascular endothelial cell and resistance to frostbite in cold acclimated rats]

Several functions of vascular endothelial cells (VEC) were investigated in rats acclimated to cold (CA) and with frostbitten feet. The results indicated that in CA rats, the number of endothelial cells in circulatory blood and the contents of 6-keto -PGF1 alpha and TXB2 in plasma were markedly higher, the activity of serum angiotensin I converting enzyme (ACE) was lower, compared with those in rats non-acclimated to cold (NCA), whereas T/P ratio of the two groups was close to each other. After the rats were frostbitten, those parameters in NCA group increased sharply except for a decrease in ACE activity. But in CA group, those parameters decreased temporarily or did not change obviously and the tissue survival area (TSA) significantly increased. The above findings suggest that the adaptive changes in increase of metabolic turnover rate and function of VEC after cold acclimation may be beneficial to the body to enhance the resistance to frostbite and repairing ability.