Accession Number : AD0690303

Title :   EFFECTS OF pH, CO2, AND BUFFERING SYSTEMS ON LACTIC ACID PRODUCTION IN RAT LIVER SLICES.

Descriptive Note : Final rept. Dec 66-Mar 68,

Corporate Author : SCHOOL OF AEROSPACE MEDICINE BROOKS AFB TEX

Personal Author(s) : Soucie,William G.

Report Date : APR 1969

Pagination or Media Count : 12

Abstract : In an effort to reveal the separate effects of pH, CO2, and the type of buffering agent on lactate production, rat liver slices were incubated in Krebs-Ringer solution using three different buffers equilibrated with either O2 or 5% CO2 in O2 and at three different pH values (7.1, 7.4, 7.7). With 5% CO2 in the gas phase, lactate production had a pH optimum of 7.4 in tris(hydroxymethyl)aminomethane (THAM) and phosphate buffer but when HCO3 was the sole buffer no pH optimum was evident in the range of pH 7.1 to pH 7.7. Optimal lactate production was shifted from pH 7.4 to pH 7.7 or higher when 100% O2 was the equilibrating gas for THAM buffer. In general, the presence of CO2 in the gas phase stimulated lactate production as compared to incubations in 100% O2. The rate of lactate production is dependent on the overall rate of glycolysis. Recent evidence indicates that phosphofructokinase is an important glycolytic rate-limiting enzyme and that the direct or indirect involvement of PCO2 and pH with phosphofructokinase activity seems highly probable. (Author)

Descriptors :   (*LACTIC ACID, BIOSYNTHESIS), CARBON DIOXIDE, PH FACTOR, LACTATES, BUFFERS, OXYGEN, ENZYMES, GLYCOLYSIS, METABOLISM

Subject Categories : Biochemistry
      Anatomy and Physiology

Distribution Statement : APPROVED FOR PUBLIC RELEASE