Methane excretion and experimental colonic carcinogenesis.

To examine the association between methane (CH4) excretion and experimental colonic carcinogenesis, we measured CH4 excretion in rats treated with the colonic carcinogen azoxymethane (AOM, 7 mg/kg weekly for 10 weeks) and paired controls. CH4 excretion was not initially detected in either experimental or control groups, but all animals acquired positive CH4 excretion status by time of sacrifice (week 26). There was no difference between groups or among AOM-treated animals with and without tumors in the median time to onset of detectable CH4 excretion or in the amount of CH4 excreted. Our results fail to provide support for a link between CH4 excretion and experimental colonic dysplasia or adenocarcinoma.