Dobutamine has a rapid onset of action and a short half-life [2]. Dobutamine (0.15-20 mg/kg; i.p.) results in subsequent increase in the left ventricular function and heart rate acceleration with an increasing dose in wildtype mice [3]. Dobutamine results in significant inotropic, lusitropic, and chronotropic cardiac response with a high dose in wildtype mice [3]. Low doses of Dobutamine significantly increases inotropic and lusitropic cardiac performance without chronotropic changes in the Tgαq44 mice [3]. Dobutamine increases heart rate only after high doses, but then inotropic and lusitropic cardiac functional reserve is lost [3]. Dobutamine increases alveolar liquid clearance in ventilated rats by beta-2 receptor stimulation [4]. Animal Model: Tgαq44 mice (heart failure models) [3] Dosage: 0.15 mg/kg, 0.5 mg/kg as a low dose, 1.5 mg/kg, 5 mg/kg, 20 mg/kg as a high dose Administration: Intraperitoneal injection Result: Induced different response in cardiac function on a low and high dose in mice with with heart failure.