THE EFFECTS OF AMRINONE AND GLUCAGON ON VERAPAMIL-INDUCED CARDIOVASCULAR TOXICITY IN ANESTHETIZED RATS

The goal of this study was to compare the effects of glucagon and amri none on mean arterial pressure (MAP) and heart rate, when used alone a nd in combination, in an anaesthetized rat model of verapamil toxicity . Fats were anaesthetized and the carotid artery was cannulated for MA P and heart rate measurements. Jugular and femoral veins were cannulat ed for drug administration. After verapamil infusion (15 mg/kg/h), con trol animals were given normal saline solution and the other groups re ceived amrinone (0.1 or 0.2 mg/kg/min), glucagon (0.3 mg/kg bolus foll owed by 0.1 or 0.2 mg/kg/min infusion), glucagon plus amrinone (0.1 mg /kg/min and 0.1 mg/kg/min respectively) or glucagon plus amrinone (0.2 mg/kg/min and 0.1 mg/kg/min respectively). Glucagon (0.2 mg/kg/min) s ignificantly increased MAP when compared to the control group (P < 0.0 1). The combination of glucagon and amrinone did not produce a synergi stic effect for the recovery of MAP. Furthermore, this combination mas ked the positive effects of glucagon (0.2mg/kg/min) on MAP. Glucagon ( 0.2mg/kg/min) increased the heart rates compared with those of the con trol group (P < 0.05). Additionally, amrinone (0.1 mg/kg/min) plus glu cagon (0.1 mg/kg/min) increased the heart rates (P < 0.05). Finally, g lucagon dose dependently recovered MAP. While amrinone depressed MAP i n combination with glucagon, it did not alter the positive chronotropi c effect of high dose glucagon.