Abstract 311: Single-Dose Isoproterenol does not Depress Cardiac Function in Mice

Rationale: Myocardial injury after repeated or continuous administration of isoproterenol (ISO) in preclinical models has been widely described in the literature by our lab and others. Recent controversial reports using a one-time dose of ISO, to mimic a Takotsubo-like cardiomyopathy, demonstrated pronounced and reversible depression of cardiac function at one-week post injection with widespread myocyte death followed by robust myocardial regeneration and recovery of cardiac function. Hypothesis: Single-dose ISO does not produce depression of cardiac function Methods and Results: C57Bl/6 mice were given a single subcutaneous injection of vehicle (saline) or 5, 200, or 300 mg/kg of ISO. Cardiac function was measured using transthoracic echocardiography with cardiac strain analysis at baseline prior to ISO injection and after 1, 7, 14, and 28 days post-injection. Animals were sacrificed after 1, 7, and 28 days post-injection for evaluation of gross heart weight (HW), HW/body weight (BW) and HW/tibia length ...