The response of red cell hexose monophosphate shunt after sulfhydryl
inhibition
AL Sagone , SP Balcerzak and EN Metz
Division of Hematology and Oncology, Ohio State University College of
Medicine, Columbus 43210.
In this investigation, we studied the importance of cellular glutathione
(GSH) in the hexose monophosphate shunt (HMPS) activity of unstimulated
human erythrocytes and the mechanism by which pyruvate stimulates the HMPS.
The rate of HMPS activity was measured by the production of radioactive CO2
from 14C-1-glucose or 14C-1-ribose using a vibrating reed electrometer and
ionization chamber. HMPS activity was not significantly impaired by
N-ethylmaleimide (NEM) in concentrations which bound all red cell GSH. Red
cells incubated under carbon monoxide (CO), an experimental condition which
eliminates peroxide production, still had HMPS activity which was 44% of
the value under air. Pyruvate stimulation of the HMPS was unaffected by
doses of NEM which bound all cellular GSH or by incubation under CO. These
data indicated that pyruvate stimulation of the HMPS occurs by pathways
which do not involve peroxide formation, GSH, or oxygen. This study
indicates that sulfhydryl blockade of GSH does not necessarily inhibit HMPS
activity and that HMPS activity in red cells may respond to reactions not
linked directly to glutathione reduction.
Volume 45,
Issue 1,
pp. 49-54,
01/01/1975
Copyright © 1975 by The American Society of Hematology
