title: D- and L-lactate catabolism to CO2 in rat tissues.
abstract: The current study was initiated in order to compare the rates of oxidative catabolism of D- and L-lactate in various rat tissues. Uniformly labeled D- or L-[14C]lactate was incubated at 37 degrees C in a closed system with tissue homogenates in Krebs-Ringer phosphate buffer. Evolved 14CO2 was trapped in a center well containing a fluted filter paper saturated with strong base and the radioactivity determined. The ratio of L-lactate to D-lactate oxidation was greatest in brain, followed by kidney, heart, and liver. In liver the rate of oxidation of D-lactate exceeded that of L-lactate, in heart the rates were not significantly different and in the other two tissues L-lactate was oxidized more rapidly than D-lactate. These results indicate that the rate of D-lactate catabolism is considerable and is relatively greater than had been reported previously.
mesh_terms: D000818:Animals; D001921:Brain / Q000378:metabolism*; D002245:Carbon Dioxide / Q000378:metabolism; D007668:Kidney / Q000378:metabolism*; D007700:Kinetics; D007773:Lactates / Q000378:metabolism*; D019344:Lactic Acid; D008099:Liver / Q000378:metabolism*; D009206:Myocardium / Q000378:metabolism*; D010084:Oxidation-Reduction; D051381:Rats; D013237:Stereoisomerism
chemical_list: D007773:Lactates; D002245:Carbon Dioxide; D019344:Lactic Acid