Circulation of sympathectomized dogs under pentobarbital anesthesia

¹ Department of Physiology, Columbia University College of Physicians and Surgeons, New York City

In sympathectomized-splenectomized dogs under pentobarbital anesthesia, the total blood volume averaged 78 ml/kg, with 20% in the splanchnic circulation and 28% in the central blood volume. These values are almost the same as those found in the splenectomized (control) dogs with the sympathetic system intact. The over-all and the splanchnic F_cells factors are also not significantly different between these two groups. The sympathectomized animals had lower arterial pressure, cardiac output, and splanchnic blood flow, but the resistances calculated for the total and the splanchnic circulations were not significantly different from those of the control dogs. The mean circulation times for the total, the central, and the splanchnic circulations were all longer in the sympathectomized dogs. The data indicate that, under pentobarbital anesthesia, sympathectomized dogs are characterized by slower blood flows without any significant changes in either the blood volume or vascular resistance.

Key Words: blood volume • cardiac output • central blood volume • extrasplanchnic peripheral circulation • F_cells factor • hepatic blood flow • mean circulation time • splanchnic blood flow • splanchnic blood volume • splenectomized dogs

Submitted on September 14, 1964