Thiol methyltransferase activity in inflammatory bowel disease

BACKGROUND Luminal anionic sulphide may contribute to epithelial damage in ulcerative colitis. Thiol methyltransferase (TMT) governs sulphide detoxification by the colonic mucosa and circulating erythrocytes. AIMS To measure levels of TMT activity in erythrocytes of surgically treated cases of colitis or in rectal biopsies of defined groups of colitis. PATIENTS Venepuncture blood was obtained from 37 blood donors and 27 subjects who had previously undergone a proctocolectomy for colitis: 18 for ulcerative colitis and nine for Crohn's colitis. Rectal biopsies from 122 cases were obtained: 47 without mucosal disease, 33 post-colon resection for cancer, 14 with moderate to severe ulcerative colitis, 15 with quiescent ulcerative colitis, seven with acute Crohn's colitis, and six with radiation proctitis. METHODS TMT activity was measured by high performance liquid chromatography with radioactive detection to measure 14C methylmercaptoethanol formation, the reaction product of cell extracts incubated with mercaptoethanol and 14C S-adenosylmethionine. RESULTS Erythrocyte TMT activity of surgically treated cases of colitis was significantly elevated (p