Effect of inter-renal aortic coarctation-induced hypertension on function and expression of vascular α1A- and α1D-adrenoceptors

We investigated the effect of inter-renal aortic coarctation on the function and expression of vascular α1A- and α1D-adrenoceptors and plasma angiotensin II (ATII) in rats. Male Wistar rats, either sham operated (SO), or with aortic coarctation for 7 (AC7) and 14 days (AC14) were used for agonist-induced pressor responses in vehicle (physiological saline)- and antagonist-treated anesthetized animals, immunoblot analysis (α1A- and α1D-adrenoceptor in aorta and caudal arteries), and immunoassay (plasma ATII). The α1D-adrenoceptor antagonist, BMY-7378 (BMY) blocked noradrenaline-induced responses in the order SO > AC7 ≫ AC14; in contrast, the α1A-adrenoceptor antagonist RS-100329 (RS), produced a marginal shift to the right of the dose–response curve to noradrenaline, along with a strong decrease of the maximum pressor effect in the order SO > AC7 = AC14. The potency of the α1A-adrenoceptor agonist A-61603 increased in rats with AC14, and responses were inhibited by RS in the order AC14 > AC7 > SO. In aorta,...