Abnormality of acid-base homeostasis Elevated lactate:pyruvate ratio 2020-02-15T09:13:18Z The lactate:pyruvate (L:P) ratio reflects the equilibrium between the product and substrate of the reaction catalyzed by lactase dehydrogenase and indirectly reflects the NADH:NAD+ cytoplasmic redox state. When cellular respiration or mitochondrial oxidative metabolism is impaired, such as in inborn errors of components of the mitochondrial respiratory chain, there is an increase in reducing equivalents (excess NADH and absence of NAD+) which results in an elevated L:P molar ratio. An abnormal increase in the molar ratio of lactate to pyruvate in the blood circulation.