Modulation by endothelium of the vascular effects of angiotensin II

Modulation by vascular endothelium of the effects of AII was studied in the isolated rabbit aortic and superior mesenteric artery strips. The contractile effect of AII was enhanced in rubbed aortic strips. Similar enhancement was obtained in hydroquinone pretreated unrubbed strips. The relaxing effect of acetylcholine in AII-induced precontracted aortic strips was abolished after rubbing and hydroquinone pretreatment. However, no significant changes were observed in the contractile response to AII on aspirin and nicotine pretreated strips.