AJP - Cell Physiology, Vol 236, Issue 5 262-C267, Copyright © 1979 by American Physiological Society
Cow red blood cells. II. Stimulation of bovine red cell glycolysis by plasma
M. J. Seider and H. D. Kim
Cow red cell glycolysis, which can be stimulated by a variety of purines
and pyrimidines, was also found to be elevated by its own plasma. Dialyzed
or charcoal-treated plasma could no longer stimulate glycolysis, suggesting
that the stimulating factors may be purines or pyrimidines. Determination
of purines or pyrimidines in plasma revealed the presence of xanthine (0.31
muM), hypoxanthine (0.60 muM), and adenosine (0.05 muM), as well as unknown
compounds. A physiologic level of hypoxanthine, with or without xanthine
and adenosine approximating their concentrations in plasma, resulted in the
stimulation of cow red cell glycolytic rate by 16% (P less than 0.01).
These findings suggest that plasma-borne purines may act on cow red cells
in concert with as yet unidentified factors. Moreover, exchanging calf and
cow plasmas produced no stimulatory effect on either calf or cow red cell
glycolysis, suggesting that a) calf red cells lack some of the cellular
components that respond to this stimulator and, b) only cow plasma contains
this specific stimulator. In other species, including dog, cat, rabbit,
rat, guinea pig, and human, stimulation of glycolysis by plasma was not
observed.
