Neurohumoral responses to chronic myocardial infarction in rats

• Published in: Circulation (New York, N.Y.) Vol. 78; no. 2; pp. 376 - 381
• Main Authors: HODSMAN, G. P, KOHZUKI, M, HOWES, L. G, SUMITHRAN, E, TSUNODA, K, JOHNSTON, C. I
• Format: Journal Article
• Language: English
• Published: Hagerstown, MD Lippincott Williams & Wilkins 01.08.1988
• Subjects: Aldosterone - blood; Animals; Arginine Vasopressin - blood; Atrial Natriuretic Factor - blood; Biological and medical sciences; Cardiology. Vascular system; Catecholamines - metabolism; Chronic Disease; Coronary heart disease; Female; Heart; Ion Exchange; Medical sciences; Myocardial Infarction - blood; Myocardial Infarction - metabolism; Myocardial Infarction - urine; Myocardium - metabolism; Neurotransmitter Agents - blood; Neurotransmitter Agents - metabolism; Osmolar Concentration; Rats; Rats, Inbred Strains; Renin - blood; Sodium - blood; Sodium - metabolism; Hormone; Infarct; Rat; Hydroelectrolytic balance; Rodentia; Cardiovascular disease; Atrial natriuretic peptide; Vasopressin; Renin angiotensin aldosterone system; Vertebrata; Chronic; Experimental disease; Mammalia; Myocardium
• ISSN: 0009-7322; 1524-4539
• DOI: 10.1161/01.cir.78.2.376

In chronic cardiac failure, various neurohumoral mechanisms are activated to sustain blood volume, blood pressure, and organ perfusion. Using the coronary artery ligation model of heart failure in the rat, we have measured changes in vasoactive hormone secretion and related these changes to salt and water status during a 1-month period. When compared with controls, rats with infarction had a marked rise in plasma atrial natriuretic peptide (294 +/- 59 vs. 79 +/- 10 pg/ml, p less than 0.001) although there was no increase in total exchangeable body sodium. Plasma renin activity and plasma aldosterone concentrations were the same for both rats with infarction and controls. Similarly, there were no significant differences in plasma arginine vasopressin, plasma osmolality, or plasma sodium concentration in rats with infarction. Ventricular norepinephrine levels were reduced in animals with infarction (p less than 0.01). Plasma atrial natriuretic peptide levels were raised in this model of chronic left ventricular failure. However, there was no salt retention and little stimulation of the renin-angiotensin-aldosterone system or vasopressin. The results suggest that high circulating atrial natriuretic peptide levels may prevent or limit salt and water retention, either directly or indirectly, by inhibiting the renin-angiotensin-aldosterone system.