Clinical & Experimental Cardiology
Open Access

Abstract

Reduced Cardiac Performance after Differential Pharmacological Stress in Streptozotocin-Induced Diabetic Rats

Alexander Riad, Dirk Westermann, Stephan B Felix, Heinz P Schultheiss and Carsten Tschope

The development of heart failure including disturbed cardiac stress response is a main complication of diabetes mellitus (DM). In the present study we characterized in vivo the cardiac stress response in the often used streptozotocin (STZ) rat model. We analysed left ventricular (LV) performance of STZ-diabetic rats under basal and pharmacological stress conditions by recording pressure-volume loops using a microconductance catheter at two different time points. Under basal conditions, STZ induces after two weeks impaired LV systolic and diastolic dysfunction indexed by decreased LV pressure and dp/dtmax as well as decreased cardiac stiffness and dp/dtmin leading to decreased cardiac output. This cardiac phenotype behaved at least in part progressively up to six weeks after STZ injection. Intravenously infusion of dobutamine led to a dose-dependent depression of LV performance two and six weeks after STZ injection. Concordant with these fi ndings, the maximum LV conductibility induced by adrenalin was signifi cantly decreased at both two and six weeks after STZ injection. The STZ-diabetic rat is an adequate model for investigating disturbed cardiac stress response as a result of diabetic conditions.