The efficacy of hexoses, their intermediates and analogues, as substra
tes for glutathione (GSH) regeneration, were tested in rabbit and guin
ea-pig erythrocytes. Glucose was found to be the most effective substr
ate in both species. Compared to glucose, the efficacy of other substr
ates were: fructose (85%), mannose (68%), galactose (47%), 2-deoxygluc
ose (43%), glucose-1-phosphate (29%), 2-deoxyglucose-6-phosphate (21%)
, fructose-6-phosphate (12%) and glucose-6-phosphate (11%) in rabbit e
rythrocytes, and mannose (93%), fructose (52%) and 2-deoxyglucose-6-ph
osphate (11%) in guinea-pig erythrocytes. Our results provide evidence
that in addition to enzyme activities, the availability of the substr
ate is also an important factor in determining GSH regeneration in mam
malian erythrocytes.