ENHANCEMENT BY HEMICHOLINIUM-3 OF CHOLINE AND ACETYLCHOLINE EXCRETION BY THE RENAL TUBULE OF THE CHICKEN

¹ Department of Pharmacology, School of Medicine, State University of New York at Buffalo, Buffalo, New York

The effect of hemicholinium- (HC-3) on the renal tubular transport of the ¹⁴C-label associated with choline and acetylcholine was investigated in vivo in the chicken by use of the Sperber technique. It was found that HC-3 given by continuous infusion into the renal portal circulation at rates up to 1 x 10^-8 mol/min did not inhibit the transport of either choline or acetylcholine but instead produced an increase in their transport, as indicated by transport efficiency. Choline transport was enhanced about 25% by HC-3 at infusion rates from 1 x 10^-22 to 1 x 10^-8 mol/min. Acetylcholine transport was enhanced about 19% by HC-3 at 1 x 10^-9 mol/min. The unanesthetized chicken could not tolerate HC-3 at infusion rates greater than 1 x 10^-7 mol/min. When the administration of HC-3 was stopped, the transport of choline showed a further increase whereas the transport of acetylcholine fell toward control levels.