ALTERATIONS IN VASOREACTIVITY OF FEMORAL ARTERY INDUCED BY HINDLIMB UNWEIGHTING ARE RELATED TO THE CHANGES OF CONTRCTILE PROTEIN IN RATS

摘要

Responses of endothelium removed femoral arterial rings to vasoactive compounds were examined in vitro, and the expression of Myosin and Actin of femoral artery were observed by Western Blotting and Immunohistochemistry in hindlimb unweighting rats and control rats. The results showed that contractile responses of femoral arterial rings evoked by Phenylephrine, Endothelin-1, Vasopressin, KCl, Ca{sup}(2+) and Ca{sup}(2+) ionophore A23187 were decreased in hindlimb unweighting rats as compared with that of controls. But vasodilatory responses induced by SNPand cGMP were not different between groups. No significant differences have been found in expressions of Calponin, Myosin, Actin, and the ratio of MHC SM1/SM2 between the two groups, but expression of alpha-SM-Actin decreased in hindlimb unweighting rats. The data indicated that the diminished contractile responsiveness probably result from altered contractile apparatus, especially the contractile proteins.