Role of cyclic GMP in the action of heat-stable enterotoxin of Escherichia coli.

摘要: ENTEROTOXIGENIC strains of Escherichia coli elaborate two enterotoxins, a heat-labile toxin (LT) and heat-stable (ST), which cause diarrhoeal disease in humans1; ST-producing E. diarrhoea adult volunteers2 have been associated with epidemic nursery for the newborn3 sporadic among North American tourists to Latin America4 Navajo people Arizona5. LT-producing are identified by ability culture filtrates fluid accumulation rabbit ileal loops at 18 h (ref. 6) or morphological alteration Chinese hamster ovary (CHO) cells7 Y-l adrenal cells8. earlier (peak 6 6), gut suckling mouse 3 (refs 9, 10). LT acts manner similar cholera (CT) activating adenylate cyclase11. The mechanism action ST is unknown, however. Culture strain that produced both caused immediate net secretion canine jejunal segments without 1-h delay characteristic response CT12,13. In addition, an increase cyclase activity as measured enzymatic generation P32-cyclic AMP from P32-labelled ATP13, also contrast appearance increased following exposure CT12. possibility early effect was mediated changes cyclic nucleotide concentrations investigated; GMP intestinal tissue analogue 8BrcGMP mimicked magnitude time course rabbits mice.