1977. Sodium pentobarbital induced alterations in regional distribution of blood in Peromyscus maniculatus (deer mouse) and Eptesicus fuscus (big brown bat). Can. J. Zool. 55: 1931Zool. 55: -1935 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 beatslmin and 334 beatslmin in deer mice and bats, respectively. Administration of 40 mglkg sodium pentobarbital results in marked tachycardia in deer mice but not in bats. A dose of 60mg/kg causes a slight increase of HR above resting values in the mice and a significant decrease in the bats. The com~arativelv low HR's in bats are considered to be due to their lowering of body temperature to nea; 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. RAUCH, J. C., et D. D. BEATTY. 1977. Sodium pentobarbital induced alterations in regional distribution of blood in Peromyscus maniculatus (deer mouse) and Eptesicus fuscus (big brown bat). Can. J. Zool. 55: 1931-1935. On a itudit IPS effets de I'anesthisie au pentoharbital sdique sur le rythme cardiaque { H R ) et la nipanition du sang (par la methode de Sapirsteinl chez In souris i pattes blanches Pcromyscns rnnnicirlrrttts et chez la c h a u v~s o u n s Ep~esrc~r.cjitsc~rs.Le rythme cardiaque au repas est de 400 hattementslmin en moyenne chez la souris ^a pattes blanches et de 334 battementslmin chez la chauve-souris. Cadministration de 40 mglkg de pentohrbital sodlque cause une rachycardie importanre chez la souris. muis pas chez la chauvesouris. Une dose de 60 mglkg entnine une Ikgkre accel6ntiun du rythme cardiaqtw chez la souris el un ralentissement irnpoFtant chet la chauve-sour+%. Les rythmes c;trd~aques rrlativemenl lenrs chez la chauve-souris s'expliquen! p;u.