Mucosal (Na+-K+)-ATPase and adenylate cyclase activities in children with toddler diarrhea and the postenteritis syndrome.

Assays for (Na+-K+)-ATPase and basal, fluoride stimulated and percentage of activation of adenylate cyclase have been established for small portions of human jejunal biopsies. Control means and ranges have been established for each activity in a group of children with failure to thrive but no gastrointestinal disease. Activities of (Na+-K+)-ATPase and percentage of activation and basal activity of adenylate cyclase are increased in children with toddler diarrhea. (Na+-K+)-ATPase activity is reduced in children with active postenteritis syndrome, and recovery from this syndrome is associated with an increase in this activity and of percentage of activation and basal activity of adenylate cyclase.