Intact rat diaphragms were exposed in vitro to varying CO2 tensions and bicarbonate concentrations, and the steady-state citrate content of diaphragm muscle was measured to investigate the relationship between metabolism and extracellular pH, PCO2, and (HCO3-). In addition, rat hemidiaphragms were incubated with 1,5-citrate-14C under different acid-base conditions, and 14CO2 production was determined as a measure of citrate oxidation.
