Expression of renin-angiotensin system components in the heart, kidneys, and lungs of rats with experimental heart failure

Background: Chronic activation of the renin-angiotensin system (RAS) plays an important role in the pathogenesis of heart failure. Increasing evidence indicates that other than the circulating RAS, a local RAS exists several tissues, including the heart. The present study was carried out to quantify cardiac, renal, and pulmonary mRNA levels of renin, angiotensin-converting enzyme (ACE), and types 1 and 2 angiotensin II receptors (AT-1 and AT-2), in rats with different severities of heart failure. Methods and Results: Heart failure was induced by the creation of an aortocaval fistula below the renal arteries. Rats normal sodium balance or decompensate and develop severe sodium retention. Six days after placement of the aortocaval fistula, heart weight (normalized to body weight) increased 35% (PM.05) in compensated and 65% in decompensated rats compared with control rats. Plasma renin activity increased 45% (P<.05) in rats sodium balance and 127% in sodium-retaining rats. Total RNA was ...