Tissue distributions of 4-(hydroxymethylnitrosamino)-1-(3-pyridyl)-1-butanone glucuronide, a stable form of reactive intermediate produced from 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone, in the rat.

The tobacco-specific nitrosamine, 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK), induces lung tumors in rodents and has been suggested as a causative factor in human lung cancer. NNK is activated by α-hydroxylation at either the methyl or methylene carbon adjacent to the N-nitroso group to yield unstable intermediates that spontaneously decompose to produce alkylating agents. 4-(Hydroxymethylnitrosamino)-1-(3-pyridyl)-1-butanone (HO-methyl NNK) glucuronide, a glucuronide of the reactive intermediate of NNK has been identified. However, there are no available data concerning HO-methyl NNK glucuronide. In the present study, we investigated the tissue distribution of HO-methyl NNK glucuronide in control and phenobarbital (PB)-treated rats after intraperitoneal administration of NNK. In PB-treated rats, HO-methyl NNK glucuronide was detected in plasma, kidney, liver, lung, and pancreas. On the contrary, in the control rats, HO-methyl NNK glucuronide was detected only in plasma, kidney and liver at low concentrations compared with PB-treated rats. The results of cumulative urinary excretion of HO-methyl NNK glucuronide in Wistar and Gunn rats suggested that PB-inducible UDP-glucuronosyltransferase 2B isoforms mainly contribute to the formation of HO-methyl NNK glucuronide.