Lactate Consumption by Hepatocytes in Monolayer Culture

Abstract

Abstract

Hepatic lactate metabolism was studied in confluent primary hepatocyte monolayer cultures from fasted rats. The cultures were maintained in Krebs-Henseleit buffer containing 1% gelatin and 50 mM of both Tricine and Hepes. Under standard conditions of pH 7.4, P_o2 > 280 mm Hg, and P_co2 of 22-27 mm Hg, little glucose or lactate was produced unless the media was made 10 mM with either fructose, dehydroxyacetone, or pyruvate. While the addition of glucose did not lead to lactate production, added lactate was converted to glucose. Lactate utilization was unaffected by lowering the P_o2 to 100 mm Hg, but between 100 to 20 mm Hg lactate consumption was increasingly inhibited. At 20 mm Hg no lactate was consumed. At low pH, below 7.0, lactate utilization was inhibited. The effects of low pH and anoxia, separately and together, were readily reversed by returning the cultures to standard conditions. Varying the P_co2 from 4.4 to 101 mm Hg had no effect on lactate consumption.