Oxidation of hydrogen sulfide and methanethiol to thiosulfate by rat tissues: a specialized function of the colonic mucosa.

摘要: Colonic bacteria release large quantities of the highly toxic thiols hydrogen sulfide (H(2)S) and methanethiol (CH(3)SH). These gases rapidly permeate colonic mucosa, tissue damage would be expected if mucosa could not detoxify these compounds rapidly. We previously showed that rat cecal metabolizes via conversion to thiosulfate. The purpose present study in rats was determine this thiosulfate is (a) a generalized function many tissues, or (b) specialized mucosa. tissues studied were from cecum, right colon, mid-colon, ileum, stomach; liver; muscle; erythrocytes; plasma. metabolic rate determined by incubating homogenates various with H(2)(35)S CH(3)(35)SH measuring incorporation (35)S into sulfate. detoxification activity H(2)S (expressed as nmol/mg per min) resulted production at least eight times greater for than non-colonic tissues. Thiosulfate CH(3)SH five more rapid conclude possesses system allows metabolize Presumably, developed protects colon what otherwise might injurious concentrations CH(3)SH. Defects pathway possibly play role pathogenesis forms colitis.