The effects of low pH and CO2 on bovine corneal lactate production.
OBJECTIVE
Hypoxic corneal swelling in human subjects is reduced by CO2 induced corneal acidosis. We investigated whether this effect could be explained by a reduction in lactate production under acidic conditions.


METHODS
Lactate production from isolated bovine corneas was assayed under normoxic and hypoxic conditions at normal pH (7.5) and low pH (7.05). Low pH was achieved using a CO2/HCO3- Ringer or a HEPES buffered Ringer.


RESULTS
Normoxic corneas produced significantly less (approximately 25%) lactate under all acidic conditions. In contrast, hypoxic corneas produced the same or slightly less lactate under acidic conditions (weighted average of all conditions = 6% less lactate).


CONCLUSIONS
From these results, we concluded that pH can have a substantial effect on lactate production, but its influence on glycolytic activity during hypoxia is suppressed and may be negligible.
Sarroca
A
A
Morton D. Sarver Center for Cornea and Contact Lens Research, University of California, School of Optometry, Berkeley 94720-2020, USA.
Lin
S
S
Bonanno
J A
JA
D000138:Acidosis / Q000378:metabolism / Q000473:pathology; D000818:Animals; D002245:Carbon Dioxide / Q000378:metabolism*; D002417:Cattle; D003315:Cornea / Q000166:cytology / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D000860:Hypoxia / Q000378:metabolism / Q000473:pathology; D019344:Lactic Acid / Q000096:biosynthesis*; D013053:Spectrophotometry
D002245:Carbon Dioxide; D019344:Lactic Acid