Article: article from journal or magazin.
Reciprocal changes in vasoactive hormones in the rat myocardial infarction model of heart failure.
Journal of cardiac failure
The purpose of this study was to determine (1) if there is a relationship between the changes in the plasma levels of atrial natriuretic peptide (ANP) and plasma renin activity (PRA) as rats compensated from 3 days to 6 weeks after coronary ligation and (2) if these changes are related to myocardial infarction (MI) size. Arterial blood was drawn twice from 34 conscious rats (control, n = 10; small MI, n = 10; large MI, n = 14). Histologic MI size correlated better with ANP 3 days (r = .72, P < .001) than with ANP 6 weeks after MI (r = .39, P = .021). The reverse was true for an electrocardiographic index of MI size that used the sum of the Q waves minus the sum of the R waves in leads I, aVL, and V5. Atrial natriuretic peptide at 3 days was increased in both MI groups and was highest in the large MI group (control, 25.6; small MI, 41.0; large MI, 58.6 pM). Atrial natriuretic peptide decreased significantly from 3 days to 6 weeks in the large MI group and normalized in the small MI group (control, 25.0; small MI, 26.4; large MI, 44.4 pM). Plasma renin activity was not elevated at either time. However, the change in ANP from 3 days to 6 weeks in the MI rats was negatively related to the change in PRA (r = .48, P = .016). Atrial natriuretic peptide levels early after MI may be a good predictor of infarct size. The pattern of ANP and PRA changing in opposite directions over time suggest a counterregulatory link between these two systems.
Animals, Atrial Natriuretic Factor, Cardiac Volume, Disease Models, Animal, Heart Failure, Male, Myocardial Infarction, Rats, Rats, Wistar, Renin
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