Which of the propeies accounts for ethanol's use in ethylene glycol poisoning?: (A) Competitive inhibitor of NADPH oxidase, (B) Competitive inhibitor of alcohol dehydrogenase, (C) Competitive inhibitor of aldehyde dehydrogenase, (D) Non-competitive inhibitor of aldehyde dehydrogenase
Answer is B. Ethanol acts by competing with ethylene glycol for alcohol dehydrogenase, the first enzyme in the degradation pathway. Because ethanol has a much higher affinity for alcohol dehydrogenase, about a 100-times greater affinity, it successfully blocks the breakdown of ethylene glycol into glycoaldehyde, which prevents the fuher degradation. Ref: Lehninger Principles of Biochemistry, 4th Edition, Page 336; Updates in Emergency Medicine By John Cahill, 2002, Page 115