Altered Responsiveness of the Aorta of Hypertensive Rats to Histamine and Acetylcholine

Abstract

This study investigates the response of the noradrenaline-contracted aorta of normotensive, renal-induced and spontaneously hypertensive rats to acetylcholine (ACh) and histamine. Aortae of the renal-induced hypertensive rats compared to the those of the normotensive rats were hypo-responsive to the two vasodilators, indicating that the sensitivity of the endothelial histamine and acetylcholine receptors is significantly lower. However, with the spontaneously hypertensive rats, the high blood pressure appears to affect only the histamine receptors.