AJP - Cell Physiology, Vol 236, Issue 5 268-C276, Copyright © 1979 by American Physiological Society
Metabolic requirements for anaerobic active Cl and Na transport in the bullfrog cornea
P. S. Reinach, H. F. Schoen and O. A. Candia
In the bullfrog cornea, the relationships between the rates of aerobic and
anaerobic glycolysis and active Cl and Na transport were studied. In NaCl
Ringer (glucose-free), the short-circuit current (SCC) declined much more
slowly under aerobic than under anaerobic conditions. The aerobic lactate
effluxes in glucose-free and glucose-rich NaCl Ringer were 0.08 and 0.23
micromol/h.cm2, respectively. The transition to anoxia caused these values
to increase significantly and was accompanied by depletion of endogenous
glycogen in glucose-free Ringer. In Na2SO4 Ringer, amphotericin B (10(-5)
M) stimulation of the aerobic SCC was not dependent on the presence of
glucose but under anoxia, SCC stimulation required glucose. In Na2SO4
(glucose-rich) Ringer, amphotericin B stimulated the aerobic lactate efflux
from 0.26 to 0.36 mumol/h.cm2 and anoxia increased it to 0.55
micromol/h.cm2. In NaCl Ringer, the addition of either 0.5 mM adenosine or
1 mM ATP with 26 mM glucose restored the anaerobic-inhibited SCC and
lactate efflux of glucose-depleted corneas. The results show that the
reactions of glycolysis are a sufficient energy source for supporting
active Na and Cl transport.
