AJP - Gastrointestinal and Liver Physiology, Vol 247, Issue 3 311-G318, Copyright © 1984 by American Physiological Society
Increasing inhibition of hepatic protein secretion by colchicine during development
S. S. Kaufman, D. J. Tuma, M. F. Sorrell and J. A. Vanderhoof
Colchicine and other antimicrotubular drugs have been shown to impair
plasma protein secretion by fetal rat liver at late gestation (day 21)
markedly less than by the mature organ. In the present study, the effect of
colchicine on plasma protein secretion by liver slices was determined at
several times during rat development. Secretion of [14C]leucine-labeled
albumin and [3H]glucosamine-labeled glycoproteins was only minimally
impaired (20%) by colchicine (50 microM) on gestation day 19. Inhibition of
protein secretion increased to about 40% just before birth and remained
unchanged throughout the perinatal period. Inhibition increased thereafter
until the maximum effect (75%) was first observed 28 days after birth.
Studies in which [3H]-colchicine was used indicated that neither reduced
colchicine levels in tissue nor reduced affinity of tubulin for colchicine
caused the diminished impairment of secretion in immature liver. These
findings suggest that participation of microtubules in liver plasma protein
secretion is reduced during development and that full participation is
delayed beyond the perinatal period in this species.
