BICARBONATE IN THE TREATMENT OF METABOLIC-ACIDOSIS - EFFECTS ON HEPATIC INTRACELLULAR PH, GLUCONEOGENESIS, AND LACTATE DISPOSAL IN RATS

The effects of agents used in the treatment of metabolic acidosis could depend on the induced changes in intracellular pH (pHi). To determine the effect of sodium bicarbonate on hepatic pHi and function, this agent was infused into anesthetized rats with acute metabolic acidosis due to either diabetic ketoacidosis (DKA) or HCI infusion. Hepatic pHi was measured by 31P-magnetic resonance spectroscopy (MRS). A substantial increase in pHi occurred (from 7.13 ± 0.08 to 7.32 ± 0.08, P < .05) despite an increase in mixed venous PCO. Isolated livers from normal rats or those with DKA were perfused at pH 6.8 and normal PCO. With infusion of sodium bicarbonate, there was again an increase in pHi (ΔpHi, + 0.27 ± 0.06, P < .02) despite increases in both portal and hepatic venous PCO. Lactate uptake was increased twofold to threefold (P < .001) by bicarbonate infusion in perfusions from both types of animals. Glucose output was increased twofold (P < .001) only in livers from normal animals. © 1993.