Subcutaneous isoproterenol: a convenient rat model for early detection of myocardial necrosis.

The uptake of Tc-99m pyrophosphate was studied in rat myocardial lesions produced by a single subcutaneous injection of isoproterenol (10--50 mg/kg of body weight). The uptake in the whole heart of treated rats is directly proportional to the isoproterenol dose. The Tc-99m PPi uptake measured at various times after lesion initiation parallels the myocardial calcium concentration changes. This model is useful for screening radiopharmaceuticals, and may also be suitable for studying early uptake in myocardial infarcts.