Journal of Applied Physiology, Vol 62, Issue 1 55-60, Copyright © 1987 by American Physiological Society
Rat lung glutathione release: response to oxidative stress and selenium deficiency
S. G. Jenkinson, T. H. Spence Jr, R. A. Lawrence, K. E. Hill, C. A. Duncan and K. H. Johnson
We performed experiments to characterize the glutathione-dependent
metabolism occurring during tert-butyl hydroperoxide infusion in isolated
perfused rat lungs and to examine the effect of selenium deficiency on this
metabolism. Selenium deficiency resulted in decreased lung glutathione
peroxidase activity but normal glutathione reductase activity and
glutathione content. Infusion of the hydroperoxide into control lungs
caused a proportional increase in tissue glutathione disulfide (GSSG)
concentration and release of GSSG into the perfusate up to an infusion rate
of 250 nmol of tert-butyl hydroperoxide X min-1 X 100 g body wt-1. Infusion
rates greater than this resulted in continued rise of tissue GSSG
concentrations but GSSG release into the perfusate plateaued. Infusion of
tert-butyl hydroperoxide into selenium-deficient rat lungs resulted in much
lower concentrations of tissue GSSG and GSSG release into the perfusate;
however, release in the selenium-deficient rat lung was also found to be
saturable at infusion rates of 450 nmol of tert-butyl hydroperoxide X min-1
X 100 g of body wt-1. Selenium deficiency in the rat decreases the rate of
reduction of infused tert-butyl hydroperoxide by glutathione and may
predispose the lung to free radical damage.
