Experimental model of myocardial infarction induced by isoproterenol in rats.

OBJECTIVE To evaluate and validate, in our laboratory, the essay of myocardial infarction induced by isoproterenol in rats by means of analysis of hematological, biochemical, oxidative stress markers and histopathological parameters. METHODS Thirty young, male, Wistar rats (145 to 230 g) were randomly allocated in two groups: Sham group, which underwent a virtual myocardial infarction induction, and the Infarction group, which underwent a myocardial infarction induction with isoproterenol. The administrations for the infarction induction were performed during two consecutive days and a 24-hour interval between them. Twenty-four hours after the last administration, rats from both groups were anesthetized and sacrificed for blood sample collection to evaluate complete blood count (CBC) and biochemical parameters (SGOT, SGPT, troponin I, urea and creatinin), obtain myocardial fragments for oxidative stress markers analyses (catalase activity and glutathione concentrations) as well as histopathological examinations. RESULTS There were no death cases in the Sham group, while the mortality rate in the Infarction group was 25%. Myocardial infarction induction with isoproterenol raised leukocytes and neutrophils counts, SGOT, troponin I and urea concentrations, reduced catalase enzyme activity and glutathione concentrations in the myocardium and let to histopathological concentrations as well. It did not exert alterations in terms of hemoglobin, SGPT and creatinin concentrations. CONCLUSIONS The isoproterenol-induced myocardial infarction essay in rats was adequately reproduced in our laboratory, causing alterations in hematological, biochemical, oxidative stress markers and histopathological parameters.