Cardiovascular effects of adenosine triphopshate infusion in the dog with heartworm disease.

Abstract

The cardiovascular effects of adenosine triphosphate (ATP) as vasodilator was studied in dogs anesthetized with pentobarbital sodium. Eight mongrel dogs with heartworm infection (group F) and 5 healthy dogs as control (group N) were used for the experiment. To determine the severity of heartworm disease, the dogs were examined with electrocardiography and other clinical examinations before the experiment. PaCO2 was maintained 35-45 mmHg by control ventilation. Mean arterial pressure (MAOP), mean pulmonary arterial pressure (MPAP), heart rate (HR), stroke volume (SV) and cardiac output (CO) were measured. The doses of intravenous infusion of ATP were 50, 100, 200 and 300 pg/kg/ min. Also 1 or 2 mg/kg of ATP was injected rapidly.The 50 μg/kg/min, of ATP slightly increased in HR and MAOP. More than 100 μg/kg/min. of ATP significantly increased in SV and CO (30±5.4% and 40±8.3%o respectively), and decreased in the total systemic resistance (SVR) and total pulmonary resistance (PVR) (35.1±6.2% and 29.5±10.9% respectively) . More than 200, ccg/kg/min, of ATP significantly decreased not only SVR but also MAOP. MPAP increased at every dose of ATP in group F, but little change was observed in group N with a low dose of ATP.Though ATP was useful in respect of reduction of the afterload under anesthesia, increased MPAP in groug F suggested that administration of ATP to the dog with heartworm disease requires careful monitoring.