[Effects of dobutamine on the respiration, blood pressure, and several blood components in dogs (author's transl)]

Abstract

In anesthetized Beagle dogs, intravenous bolus administration of dobutamine (DOB) caused an increase of systolic pressure and a decrease of diastolic pressure--increase of pulse pressure. These effects of DOB were not so pronounced as the marked depressor effect of isoproterenol (Iso) and pressor effects of epinephrine (Epi), norepinephrine(NE) and dopamine (DA). The degree of the positive chronotropic effect of DOB was the same as that of DA. Incidences of ventricular extrasystole observed at the maximal dosages of catecholamines, intravenous administration of 300 microgram/kg of DOB, 3 of Iso, 10 of Epi, 10 of NE, and 300 of DA, were 1/4, 1/4, 4/4, 4/4, and 2/4, respectively. With no evidence of ventricular extrasystoles, an increase of pulse pressure was also observed in conscious dogs given an intravenous infusion of DOB (10 or 30 microgram/kg/min for 20 min). Iso infusion resulted in an increase of serum free fatty acid, and a decrease of serum Na and K. Although DA infusion increased blood glucose and serum free fatty acid, DOB infusion produced no significant concentration change of blood components. These experimental results indicate that effects of DOB on the blood pressure, heart rate, and several blood components are weaker than other catecholamines.