Changes in blood methanol concentrations in chimpanzees during periods of chronic ethanol ingestion

Abstract

Accumulation of blood methanol was observed in young chimpanzees ( Pan troglodytes) during 6–14 week periods of chronic ethanol ingestion when blood ethanol levels were continually above 10–20 mg/100 ml blood. This occurred when the daily dose of ethanol was greater than that amount which could be eliminated during the 24-hr period. If these conditions were maintained, blood methanol concentrations increased for 4–5 days, then reached a plateau and remained elevated at fluctuating levels until blood ethanol concentrations decreased to less than 60-15 mg/100 ml. If ethanol concentrations continued to decline below these levels, methanoi concentrations then decreased linearly at a rate which was positively correlated with the rate of elimination of blood ethanol. Accumulation of blood methanol is probably the result of competitive inhibition of methanol oxidation by ethanol. The relationship between the observed increases in elimination rates of both ethanol and methanol and the possibility of ethanolstimulated enzymatic alterations are discussed.