Sodium pentobarbital induced alterations in regional distribution of blood in Peromyscus maniculatus (deer mouse) and Eptesicus fuscus (big brown bat)

Abstract

This study demonstrates the effect of sodium pentobarbital anaesthesia on heart rate (HR) and blood distribution (Sapirstein method) in the deer mouse, Peromyscus maniculatus, and in the big brown bat, Eptesicus fuscus.Resting HR's average 400 beats/min and 334 beats/min in deer mice and bats, respectively. Administration of 40 mg/kg sodium pentobarbital results in marked tachycardia in deer mice but not in bats. A dose of 60 mg/kg causes a slight increase of HR above resting values in the mice and a significant decrease in the bats. The comparatively low HR's in bats are considered to be due to their lowering of body temperature to near environmental levels.The general pattern of blood distribution is comparable between the two species investigated. Sodium pentobarbital administration results in a pronounced redistribution of blood which includes an increase in the fractional delivery of cardiac output to viscera of the abdomen primarily at the expense of skeletal muscle.