Effects of pentobarbital on blood pressure in dogs with coarctation of the aorta

Abstract

The effects of pentobarbital in normal and chronically hypertensive dogs were studied. The model for hypertension was neonatally induced coarctation of the proximal descending thoracic aorta. An increase in arterial pressures, 30 min after induction of anesthesia (25 mg/kg pentobarbital I. V. L.) was demonstrated in all controls. Nine of the hypertensive dogs showed similar arterial pressure increases with the remaining animal demonstrating no increase in systolic arterial pressure but elevations of diastolic and mean arterial pressures. These results do not agree with the only other reported study in dogs with chronic hypertension. The similar percentage increase in diastolic pressure in normal and coarctation dogs suggests that there is a relatively normal vasomotor response by the vascular bed proximal and distal to the coarctation. The relatively larger increase in systolic pressure distal to a coarctation remains unexplained. It is concluded that the use of pentobarbital must be avoided in physiological studies when the cardiovascular-altering effects of the agent may effect the parameters under study [4, 10].