L-Lactate dehydrogenase from Pig heart L-Lactate + NAD+ ---> Pyruvate + NADH + H+ L-Lactate + NAD+ <--- Pyruvate + NADH + H+ This enzyme is used for enzymatic determination of numerous metabolites, e.g.ATP, ADP, glucose, creatinine, pyruvate, lactate and glycerol, and of enzyme activities, e.g.GPT, PK and CPK when coupled with the related enzymes.