Alcohol and aldehyde dehydrogenase activity measured with fluorogenic substrates in the liver of rats poisoned with methanol

The effect of methanol poisoning of rats on the hepatic activities of enzym es metabolizing alcohols was evaluated. The activities of alcohol (ADH) and aldehyde dehydrogenase (ALDH) in the liver of rats dosed with 1.5 and 3 g of methanol/kg b.w. were measured with new fluorogenic substrates (4-methox y-1-naphthaldehyde [MONAL-41] for ADH and 6-methoxy-2-naphthaldehyde [MONAL -62] for ADH and ALDH) after 6, 12 and 24 hours and 2, 5 and 7 days. The me thanol intoxication led to a dose dependent induction of ADH and ALDH activ ities. The higher dose of methanol induced the activities measured with bot h MONAL-41 and MONAL-62 with the peak on day 5; its effect was largest on t he activity of ADH measured with MONAL-41. Only ADH activity measured with this substrate was induced by the lower dose of methanol during the whole t ime of the experiment the activity of ADH measured with MONAL-62 and that o f ALDH were induced only on day 1 of the intoxication. It is evident chat s ublethal methanol intoxication induces the hepatic activities of ADH and AL DH measured with fluorogenic substrates, and this induction depends on the dose of this alcohol.