Prevention by pyrazole of the effects of chronic ethanol administration on the redox states of the hepatic nicotinamide--adenine dinucleotide (phosphate) couples and on liver and brain tryptophan metabolism in the rat.

Chronic administration of pyrazole in the diet of rats does not cause toxicity and prevents the chronic effects of ethanol on: (1) the redox states of the hepatic NAD(P) couples; (2) liver tryptophan pyrrolase activity; (3) brain tryptophan and 5-hydroxytryptamine metabolism.