PLASMA-RENIN ACTIVITY IN HEART FAILURE-PRONE SHHF MCC-FA(CP) RATS/

Plasma renin activity (PRA) increases during heart failure; however, P RA is altered by drug therapy, and it is difficult to study the natura l progression of elevated PRA in humans and the possible factors that contribute to its rise. This study evaluated PRA in a drug-naive hyper tensive rat model (SHHF/Mcc-fa(cp)) that has a genetic program resulti ng in heart failure (HF). Mean arterial blood pressure and PRA were de termined and correlated to heart weight; index in conscious normotensi ve, spontaneously hypertensive rats and HF rats of various ages. PRA, atrial natriuretic peptide, and aldosterone levels progressively incre ase with age in male HF rats. PRA and blood pressure are independently correlated to cardiac hypertrophy in male KF rats. Atrial natriuretic peptide was elevated in spontaneously hypertensive compared with norm otensive rats. Female HF rats have elevated PRA, but the increase is t emporally delayed compared with that in male KF rats. Hypertension, PR A, and male gender are independent factors contributing to cardiac hyp ertrophy and heart failure in the HF model. The HF rat model mag prove useful in determining the contribution of these factors in the progre ssion from cardiac hypertrophy to heart failure.