Gluconeogenic enzymes in fibroblasts from infants dying of the sudden infant death syndrome (SIDS).

The activities of mitochondrial phosphoenolpyruvate carboxykinase (PEPCK), pyruvate carboxylase (PC), and total malic enzyme (ME) were determined in cultured fibroblasts from 74 infants diagnosed as having died from the Sudden Infant Death Syndrome (SIDS) and 36 infants who died from known causes. In addition, the glycemic state of infants was measured by determining the 'maximum' glucose present in plasma and cerebral spinal fluid (CSF) based on the following formula: glucose (maximum) = glucose + 1/2 (lactate). There were no statistical differences between SIDS and control infants in any of the three enzymatic activities measured in fibroblasts or in the estimated 'maximum' glucose values in plasma or CSF. The present results do not support the involvement of hypoglycemia as a cause of death in SIDS.