ANGIOTENSIN-CONVERTING ENZYME-INHIBITOR NORMALIZES VASCULAR NATRIURETIC PEPTIDE TYPE-A RECEPTOR GENE-EXPRESSION VIA BRADYKININ-DEPENDENT MECHANISM IN HYPERTENSIVE RATS

We previously demonstrated that angiotensin converting enzyme (ACE) in hibitor normalizes the up-regulated gene expression of vascular natriu retic peptide type A (NP-A) receptor in hypertensive rats. To elucidat e the mechanism, we examined the effect of angiotensin ii receptor (AT I) antagonist (TCV-116) and bradykinin receptor (B2) antagonist (Hoe 1 40) on the NP-A receptor mRNA level in the aorta of genetically hypert ensive rats (SHR-SP/Izm) using ribonuclease protection assay. The effe ct of ACE inhibitor on the NP-A receptor mRNA Level was completely abo lished by a concomitant administration of Hoc 140, while TCV-116 did n ot show any significant effect on the NP-A receptor mRNA level. These results suggest that bradykinin plays an important role in the regulat ion of the vascular NP-A receptor gene expression. (C) 1996 Academic P ress, Inc.