Studies on ethanol formation and its mechanism in corpses and stored biological samples

The purpose of the present study was to investigate experimentally the formation of ethanol in corpses and stored biological samples important in medicolegal examination, and to study the mechanism of ethanol formation. In the tissues and bodily fluids of corpses, ethanol, n-propanol, iso-propanol, acetaldehyde, acetone and others may be formed to various degrees according to the postmortem conditions. The criteria of post-mortem ethanol formation are 20℃ and 24 hours of post-mortem time, and a significant amount of ethanol can be formed at higher temperatures and longer times. The presence of n-propanol in samples may be useful for ascertaining post-mortem ethanol formation. The amount of ethanol formed post-mortemly may be presumed to be under 20 times of the amount of n-propanol simultaneously detected. Post-mortem ethanol formation is not increased by ante-mortem ethanol intake. Ethanol may be produced in biological samples including cadaveric blood. Fresh aseptic blood is not conducive to ethanol formation within five days. The formation of n-propanol due to yeast in the stomach of corpses is lower than that due to bacteria in other organs and bodily fluids. The addition of antibiotics, which suppress the bacterial growth in the samples, and the addition of chemical inhibitors of ADH and ALDH contained in bacteria comletely blocked ethanol formation. It may be considered that ADH and ALDH in the bacteria in corpses produce ethanol from carbohydrates such as glucose and pyruvic acid through the reverse pathway of ethanol metabolism in living subjects.