An Experimental Study on Ethanol Elimination at Subphysiological Temperatures

Abstract

Hepatocytes isolated from fed and fasted rats have been used to study the rate of ethanol elimination at different incubation temperatures. In the presence of exogenous pyruvate, hepatocytes from fed and 42 hr fasted rats, eliminated ethanol at 37 degrees by a rate of 11.6 +/- 3.4 and 6.4 +/- 0.8 nmol/min./mg of cell protein (+/- S.D.; n = 5), respectively, which are comparable to the rates obtained in vivo. The ethanol oxidation rate in cells from rats of both nutritional states correlated linearily to the incubation temperature (t = 24-37 degrees) with a temperature coefficient (Q10) of 1.8-2.3. (Q10, (= temperature coefficient) is the factor by which the enzyme activity is increased on raising the temperature 10 degrees). These findings indicate that the oxidation is not controlled by processes which involve membrane transitions in the temperature range 24-37 degrees. Our results indicate that a hypothermic individual with a body temperature of 27 degrees would have a 40-50 per cent inhibition of the ethanol elimination rate. Thus, the observed dependency of the ethanol oxidation on the body temperature has to be regarded in back-calculations of blood ethanol concentrations in forensic toxicology.

Uncertainty in the Results of Breath-Alcohol Analyses

“…Based on lognormal statistical analysis of the data of Giguiere and Simpson (12), Labianca and Simpson (7 ) determined a mean absorptive state blood/breath ratio of 1836:1, with a statistical range of 1128:1 to 2989:1 for 99% of the population. These data, coupled with the results of Heifer (10), which are also consistent with the conclusions of Normann et al (13), demonstrate unequivocally that DUI arrestees in the absorptive state are at a significantly greater disadvantage than postabsorptive arrestees when undergoing breath-alcohol analysis. Furthermore, this conclusion reinforces similar arguments put forth by Dubowski (2) and Simpson (14)(15)(16) ).…”

Water analysis

“…Phenotype frequencies of C6 were determined (372). C6 polymorphisms were determined from bloodstains stored at 4 °C for up to 10 weeks, at room temperature for up to 2 weeks, and at 37 °C for up to 4 days (373). The effects on the blood grouping results for bloodstains subjected to fingerprinting techniques (powders, chemicals, and laser) were investigated.…”