Alcohol metabolism in humans has been studied by examining blood, urine and breath samples taken at frequent intervals for 3 hours after an alcohol load of 0.5ml/kg in a fasting condition.
A gas chromatographic method was developed for the simultaneous estimation of acetaldehyde, ethanol and acetone levels in blood and urine specimens and various column packings were investigated. Porapak Q was the most suitable material and the method finally adopted used the headspace gas phase over urine or perchlorate precipitated blood specimens to which had been added sodium sulphate to displace the volatile components from the aqueous phase. Protein precipitation was necessary in order to prevent the loss of acetaldehyde from the blood samples. A gas sampling valve was fitted to enable similar determinations in breath samples but was not used in this study.
Assays by enzymatic methods were developed for lactate, pyruvate, B-hydroxybutyrate, glucose and glycerol utilising the changes in concentration of NADH which was measured by fluorometry and the merits of converting NAD+ to a fluorescent compound was examined. Twenty male and eight females volunteered for the study. Blood samples were obtained from an intravenous catheter, a procedure supervised by a physician. Blood alcohol levels were monitored by breath tests with an electrochemical device, (an Alcolimiter) for detecting ethanol.
Alcohol concentration in urine samples were measured and compared to the blood levels and the diuretic effect of alcohol was noted. These findings, together with those reported in the literature have been discussed together with their significance in interpreting disturbances of metabolism when alcohol is consumed. More assays are thought to be required including those for blood acetate, blood triglycerides with free fatty acids and some hormones. It is considered that the use of labelled compounds could add a new dimension to the in vivo investigations on human volunteers.
