Journal of Applied Physiology, Vol 50, Issue 3 621-629, Copyright © 1981 by American Physiological Society
Effects of colchicine or cytochalasin B on pulmonary macrophage endocytosis in vivo
P. A. Valberg, J. D. Brain and D. Kane
Pulmonary macrophages defend lung surfaces by ingesting deposited
particles. We investigated to what extent this uptake of particles can be
modulated in vivo by two drugs, colchicine and cytochalasin B (CytB). 198Au
colloidal gold, in isotonic saline carrier fluid, was intratracheally
instilled into male Syrian golden hamsters. The uptake of these particles
by pulmonary macrophages was measured when the carrier fluid contained only
colloidal gold and when this test particle was combined with graded doses
of either drug. We found that macrophage uptake of the particles 1 h after
instillation was depressed 37% when colchicine was added to the instillate
(150 micrograms/100 g BW). Depression of particle uptake was also seen with
CytB at 15 micrograms/100 g BW. Experiments with tritiated colchicine and
CytB showed that both drugs were rapidly cleared from the lungs early in
the 1 h phagocytic period. The effect of intravenous colchicine and CytB on
the clearance of intravenously injected gold colloid by the liver and
spleen reticuloendothelial system was negligible. The results of these
experiments, in conjunction with in vitro effects of colchicine and CytB,
provide insight into the components of cell function active in particle
uptake in situ.
