Donald G. Vidt

Effect of Ether Anesthesia on the Cardiac Output, Blood Pressure, and Distribution of Blood Flow in the Albino Rat

Rats anesthetized with ethyl ether were compared with rats anesthetized with sodium pentobarbital from the standpoint of cardiac output, peripheral resistance and regional blood flow. Cardiac output was measured by the indicator-dilution technic; regional blood flow was determined by the indicator-fractionation technic employing Rb86 or I131-antipyrine. The cardiac output is one and a half times as great in ether anesthesia as in pentobarbital anesthesia; the peripheral resistance is about two-thirds as great with ether. Compared to pentobarbital, ether increases myocardial, cerebral, and carcass blood flow, while decreasing renal, splanchnic and cutaneous blood flow. The pronounced difference in the cardiovascular effects of the two agents indicates the need for caution in the interpretation of experiments in which cardiovascular measurements are made under anesthesia.

Distribution Volumes of T-1824 and Chromium51 Labelled Red Cells Immediately Following Intravenous Injection

The difference in distribution volumes of T-1824 and Cr51 labelled red cells is fully realized within 30 sec. after their simultaneous intravenous injection in the dog. This indicates the existence of a rapidly circulating extravascular protein pool.

Renal Clearance of Para-Amino Salicylic Acid in the Dog.

Summary Simultaneous measurements of the renal clearance of PAS and creatinine in the dog indicate that the former substance is not excreted by the renal tubules. Benemid does not appear to diminish the renal clearance of PAS in the dog. This raises question as to the rationale of employing Benemid as an adjunct to PAS therapy in man. The volume of distribution of PAS appears to correspond closely with that of creatinine.