^mie Press, New York.

BIIbmdARY t a r r 7 a'j';QI 7 1`he peroxidative system involving hepatic catalase plays a major role in t e dation of 6 i c el a /^ ` i methanol in the rat (1), but in the monkey the peroxidative mechanism does not appear to ^0, J be important. This conclusion is based on the following observations: (a) ethanol and °r y methanol were about equally reactive with the peroxidative system, but ethanol was much C; /110 more reactive with the alcohol dehydrogenase system than methanol. Ethanol was a much more effective inhibitor of methanol oxidation in the intact monkey than it was in the rat, /^ which is what wo expected f i methanol is oxidized by the alcohol dehydrogenase ' vstem in the monkey, but by the peroxidative system in the rat. b) By-similar reasoningf ,] i.butanol *^ ' ^^i1fih1bitorr of a an atd a monkey than it should have been if the peroxidative system was involved. (c) 3-Amino-1,2,4-triazole, a potent inhibitor of hepatic catalase, greatly reduced methanol oxidation in the rat, but had no messurable effect on methanol oxidation in the monkey. (d) Ethylene glycol stimulated the rate of methanol oxidation in the rat, probably as a result of an increased H202 production that occurs when glycolic acid, a metabolite of ethylene glycol, is oxidized to glyoxylic acid (6, 7); no such stimulation was seen in the monkey. Studies in vitro which measured the methanol-oxidizing activity of hepatic alcohol dehydrogenase isolated from monkeys also support the view that this enzyme is largely responsible for methanol oxidation in this