The natriuretic, diuretic, and hypotensive effects of atrial natriuretic peptide (ANP) were examined in rats 4 wk after myocardial infarction induced by left coronary artery ligation. Synthetic rat ANP (fragment 1-28) was infused intravenously in doses of 0.1, 0.3, and 1.0 μg · kg-1 · min-1 for 30 min. There was a significant decrease in systolic blood pressure in controls and rats with infarction, although only in control rats was there a significant decrease in diastolic blood pressure. Changes in systolic and diastolic blood pressure were attenuated in rats with infarction compared with controls (P < 0.01). The diuretic and natriuretic effects of ANP were observed in both groups of rats, but the effects were significantly less in rats with infarction (P < 0.01). The ANP infusion did not induce significant changes in heart rate or hematocrit in controls or rats with infarction. The results indicate that rats with chronic left heart failure are less sensitive to the natriuretic, diuretic, and hypotensive effects of ANP when compared with controls. The attenuated renal response to ANP may contribute to the impaired sodium and water excretion in chronic heart failure, although other mechanisms are involved.
|Journal||American Journal of Physiology - Heart and Circulatory Physiology|
|Publication status||Published - 1989 Jan 1|
ASJC Scopus subject areas
- Cardiology and Cardiovascular Medicine
- Physiology (medical)