The blood pressure was decreased after chronic treatment with enalapril, MK-954, and hydralazine in deoxycorticosterone acetate (DOCA)-salt-induced malignant hypertension of spontaneously hypertensive rats (SHR); however, ventricular weight and plasma brain natriuretic peptide (BNP) concentration were decreased after enalapril and MK-954 but not after hydralazine. The BNP secretory rates from the ventricle in enalapril- and MK-954-treated DOCA-salt SHR were decreased to approximately 50% of those in untreated DOCA-salt SHR. The BNP secretory rate from the ventricle was positively correlated with ventricular weight in untreated and treated DOCA-salt SHR. In contrast, acute administration of captopril or MK-954 did not decrease the BNP secretory rate from the heart. Results suggest that the decrease in plasma BNP after enalapril and MK-954 is attributed to a decline in the secretion from the ventricle but not from the atrium. The reduction in ventricular mass appeared to be related to this decline.
The effects of vasopeptidase inhibitor omapatrilat on cardiac hypertrophy and brain natriuretic peptide concentration in spontaneously hypertensive rats