[Effects of anoxia and reoxygenization on the vascular contraction induced by two subtypes of alpha 1-adrenergic receptor].

The changes of the contraction induced by activation of alpha 1-adrenergic receptors during anoxia and reoxygenization were observed in isolated rat renal arteries (containing mainly alpha 1A), aortae (containing mainly alpha 1B) and pulmonary arteries (containing both alpha 1A and alpha 1B). In the renal arteries, pD2 values were increased and the maximal contractile responses were decreased during anoxia, which could be recovered 60 min after reoxygenation. In the aorta, pD2 values were decreased and the maximal responses were unchanged during anoxia, but did not return to normal 60 min after reoxygenization. The pulmonary arteries showed both the changes of renal arteries and of aorta. The results suggest that the changes during anoxia and reoxygenization are different in the different subtypes of alpha-adrenergic receptor.