Participate of nitric oxide participate in hypoxic regulation of cerebrovascular tension

Making use of nitric oxide synthesase (NOS) inhibitor Nw-nitric-oxide-L-arginine (L-NNA), the effect of NO and the pressence of endothelial cell on hypoxia-induced vascular dilatation was studied with new-born calve basilar artery. The experimental results show that L-NNA can attenuate the hypoxia-induced vascular dilatation, but the magnitude of attenuation is smaller than that of constriction caused by L-NNA on normoxic calve basilar artery. Under hypoxia, the vascular dilatation of endothelial cell denuded artery is smaller than that of endothelial cell intact artery; the difference between them is approximate by the same as the change caused by L-NNA on endothelial call intact artery. After destroying the endothelial cell, L-NNA has no obvious effect on the vascular tension. These results suggest that NO and endothelial cell are involved in hypoxia-induced vascular dilaxation.