A morphometrical method to estimate isoproterenol-induced infarct size in the rat

A morphometrical method to quantify the geometrical distribution of ventricular necrosis induced in rat following the s.c. injection of isoproterenol was developed and tested. Each ventricle was divided into two portions, apical and basal, and then 10 microns thick sections of both portions were cut. Necrotic areas were detected with nitro blue tetrazolium. Total and necrotic areas were measured for each section. Thereafter, the total and necrotic volume were calculated assuming that the ventricles form a cone-like structure composed of successive frustum of a cone crowned by an apical cone. The study of volumes, necrotic and whole cardiac could be relevant for a more actual experimental comparison of the anti-ischemic drugs activity. Our results indicated that necrotic volume is unevenly distributed, especially at lower doses of isoproterenol treatment, being greater at the apical than at the basal portions of the ventricles. The importance of careful study of the ventricular apex is stressed. Potential sources of error in determining necrotic volume are discussed.