AJP - Renal Physiology, Vol 270, Issue 1 90-F97, Copyright © 1996 by American Physiological Society
Polyol pathway and osmoregulation in JS1 Schwann cells grown in hyperglycemic and hyperosmotic conditions
A. P. Mizisin, L. Li, M. Perello, J. D. Freshwater, M. W. Kalichman, L. Roux and N. A. Calcutt
Veterans Administration Medical Center, La Jolla, California, USA.
To test the osmoregulatory rules of Schwann cell aldose reductase (AR) and
myo-inositol, JS1 Schwann cells were grown under control and hyperosmotic
conditions with and without excess glucose or galactose. JS1 cells cultured
in control conditions possessed AR protein and activity that were not
altered by the inclusion of 25 mM glucose or galactose. Following culture
with 100 mM NaCl, there was a decline in cell number accompanied by an
increase in AR activity, both of which were attenuated by the addition of
25 mM glucose or galactose. Sorbitol was not detected in JS1 Schwann cells
following culture in control, glucose-supplemented, or hyperosmotic medium,
and dulcitol accumulated only following culture with galactose. However,
both polyols were dramatically increased in JS1 cells cultured in
hyperosmotic medium supplemented with 25 mM glucose or galactose. In
contrast, myo-inositol levels were elevated only during hyperosmotic
exposure but decreased when glucose or galactose was also present. These
data are consistent with the use of polyol formation by JS1 Schwann cells
as a means of responding to osmotic stress.
