Enterohepatic circulation of 2,4-dinitrobenzaldehyde, a mutagenic metabolite of 2,4-dinitrotoluene, in male Wistar rat.

1. The major biliary metabolite of 2,4-dinitrotoluene (2,4-DNT) in male Wistar rat was 2,4-dinitrobenzyl alcohol glucuronide and the minor metabolites were 2,4-dinitrobenzyl alcohol, 2,4-dinitrobenzaldehyde, 2-acetylamino-4-nitrotoluene, 4-amino-2-nitro(2-amino-4-nitro)benzyl alcohol sulphate, 2,4-dinitrobenzoic acid, 2,4-diacetylaminobenzoic acid and 2-amino-4-nitrobenzoic acid. 2. 2,4-Dinitrobenzyl alcohol, 2,4-dinitrobenzaldehyde, 2,4-dinitrobenzyl alcohol glucuronide and 4-amino-2-nitro(2-amino-4-nitro)benzyl sulphate were excreted in the bile of male Wistar rat dosed with 2,4-dinitrobenzyl alcohol. 3. 2,4-Dinitrobenzaldehyde, 2,4-dinitrobenzyl alcohol, 2,4-dinitrobenzyl glucuronide, 4-amino-2-nitro(2-amino-4-nitro)benzyl alcohol sulphate and 2,4-diacetylaminobenzoic acid were excreted in the bile of male Wistar rat dosed with 2,4-dinitrobenzaldehyde. 4. These results indicate that the common biliary metabolites of 2,4-DNT, 2,4-dinitrobenzyl alcohol and 2,4-dinitrobenzaldehyde are 2,4-dinitrobenzyl alcohol and its glucuronide, and 2,4-dinitrobenzaldehyde, and suggest the enterohepatic circulation of 2,4-dinitrobenzaldehyde in the metabolism of 2,4-DNT.