Journal of Applied Physiology, Vol 73, Issue 2 148S-150S, Copyright © 1992 by American Physiological Society
Proliferation of jejunal mucosal cells in rats flown in space
H. R. Sawyer, C. L. Moeller, R. W. Phillips and K. L. Smirnov
Department of Physiology, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins 80523.
To examine the effects of spaceflight on the proliferation and turnover of
jejunal mucosal cells, we compared the percentages of mitotic cells present
in the crypts of Lieberkuhn in the proximal, middle, and distal jejunum in
each of five rats flown on the COSMOS 2044 mission and in rats included in
the vivarium, synchronous, and caudal-elevated groups. On the basis of the
data obtained, there was no difference in mitotic indexes between animals
in the flight and vivarium (ground control) groups. Thus it appears that
the ability of jejunal mucosal cells to proliferate is not affected by
microgravity conditions associated with spaceflight. Although the length of
villi and depth of crypts were reduced in flight animals compared with
those in the vivarium group, the observed reduction is probably
attributable to changes in the connective tissue core of villi and is not
likely due to an impairment of the proliferation and migration of jejunal
mucosal cells.
