In vitro rates of oxidation and gluconeogenesis from l(+)- and d(-)lactate in bovine tissues

1. 1. Slices of bovine kidney cortex, liver, heart and sternomandibularis muscle actively metabolized d- and l-lactate. 2. 2. Rates of d-lactate oxidation were greatest in kidney cortex followed by heart and liver with muscle exhibiting the lowest rates. 3. 3. l-lactate oxidation was greatest in kidney cortex followed by heart with liver and muscle exhibiting similar rates. 4. 4. Rates of oxidation of gluconeogenesis were similar for d- and l-lactate at 0.1 mm lactate but d utilization, as a percent of l, decreased as substrate concentrations increased to 50 mM. 5. 5. Bovine tissues appear to possess significant potential for d(-)lactate utilization. Estimates of this and possible interactions are discussed.