International Journal of Cell Cloning, Vol 7, 168-178, Copyright © 1989 by AlphaMed Press
Lithium stimulation of diffusion chamber colony growth is mediated by factors other than colony-stimulating factor
MA Doukas, RK Shadduck, A Waheed and C Gass
Department of Medicine, University of Kentucky, Lexington.
Lithium is a recognized, potent stimulator of granulopoiesis. The present
study used the model of clonal growth of granulopoietic precursors in
diffusion chambers to investigate the relevance of certain
colony-stimulating factors to lithium stimulation in vivo. In this system,
lithium stimulation of granulopoiesis could not be attributed to changes in
serum or chamber fluid colony-stimulating factor levels. Antibody to
colony-stimulating factor-1 administered during culture markedly reduced
morphologic expression of colonies in control and lithium-pretreated host
mice, yet subculture of chamber contents revealed that lithium stimulation
of a granulopoietic progenitor, perhaps of primitive potentiality, had
nevertheless occurred. Therefore, we hypothesize that lithium acts in an
indirect, hormonal fashion and that these colony-stimulating factors, while
necessary for morphologic expression, play no role in the stimulatory
effect. This hypothesis raises the possibility that lithium in combination
with recombinant colony-stimulating factors may result in clinically
effective synergistic stimulation of granulopoiesis.
