Collagen levels in isoproterenol induced myocardial infarction in rats.

Myocardial infarction was induced in albino rats by the subcutaneous administration of isoproterenol. A significant was observed increase in weight of the myocardium, total protein, DNA levels, neutral salt soluble collagen content, serum and urinary hydroxyproline levels at peak infarction stage in treated rats while the body weight, insoluble and total collagen content of heart were found to be decreased. These results show an early degradation of collagen immediately after myocardial infarction and enhanced synthesis during the different stages of recovery. Histological studies confirmed the incidence of peak infarction after two doses of isoproterenol treatment and recovery to normalcy from the third day onwards.