MAINTENANCE OF HIGH EXTRACELLULAR PH DOES NOT INFLUENCE CELL PH OR METABOLISM IN SUBMERGED ANOXIC BULLFROGS

We compared extracellular and intracellular acid-base states in paraly zed bullfrogs subjected to 4 h of anoxic submergence at 15-degrees-C w ith or without maintenance of extracellular pH at preanoxic levels by bicarbonate infusion. We also assessed anaerobic metabolism under thes e conditions by measuring tissue lactate and glycogen concentrations i n liver, heart, and skeletal muscle. Although bicarbonate infusion res ulted in a significantly higher arterial blood pH (pH(e)) than saline infusion, intracellular pH (pH(i)) of heart and skeletal muscle, as de termined by the DMO equilibration technqiue, were not significantly di fferent after 4 h of anoxia. We were also unable to demonstrate any di fferences in anaerobic metabolic rate, since both tissue lactate accum ulation and glycogen depletion were identical in bicarbonate- and sali ne-infused frogs in the tissues studied. We conclude that (1) alterati ons in the extracellular acid-base state by bicarbonate infusion are n ot necessarily reflected in the intracellular compartment, perhaps due to powerful intracellular buffering processes, and (2) maintenance of an alkaline extracellular pH during anoxia in bullfrogs does not infl uence the anaerobic metabolic rate. We could not, however, rule out a possible role for intracellular pH in regulating anaerobic metabolism during anoxia in frogs.