Printed ii U.S.A. ENHANCEMENT BY HEMICHOLINIUM-3 OF CHOLINE AND ACETYLCHOLINE EXCRETION BY THE RENAL TUBULE OF THE CHICKEN

by hemicholinium-3 of choline and acetyicholine excretion by the renal tubule of the chicken. J. Pharmacol. Exp. Then. 186: 254-260, 1973. Time effect of hemicholinium- (HC-3) on the renal tubular transport of the “C-label associated with choline and acetvlcholine was investigated in vivo in the clmicken 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 l0 mol/min did not inhibit the transport of either choline or acetylcimoline 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 ” to 1 x 10 mol/min. Acetyicholine transport was en-hanced about 19 % by HC-3 at. 1 x 10 ’ mol/min. The unanesthetized chicken could not tolerate HC-3 at infusion rates greater timan 1 x 10 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. The mechanism by wimieh hemicimolinium-3 (HC-3) produces a decrease in the acetyicholine content of neuronal tissue has been the subject of many investigations (Birks and Maclntosim, 1961; Gardiner, 1961; Elmqvist and Quastel