AJP - Gastrointestinal and Liver Physiology, Vol 251, Issue 2 253-G262, Copyright © 1986 by American Physiological Society
Mast cells in the regulation of intestinal electrolyte transport
D. A. Russell
Experiments were performed to determine the ionic basis and physiological
messengers of transepithelial ion transport alterations (short-circuit
current, Isc) measured during the induction of intestinal anaphylaxis in an
Ussing chamber. Antigens derived from Trichinella spiralis, an intestinal
parasite, were used to challenge jejunal tissue from guinea pigs immunized
by infection with the parasite. Histamine (10(-4) M) caused an increased in
Isc that was similar to that induced by antigen. Diphenhydramine (10(-5) M)
inhibited the epithelial electrical responses to histamine by 100% and to
antigen by 60-70%. Indomethacin (10(-5) M), in combination with
diphenhydramine, completely inhibited the antigen-induced rise in Isc.
Furosemide (10(-4) M) caused 50-60% inhibition of the increase in Isc
induced by antigen and histamine. Antigen challenge of isolated enterocytes
did not alter intracellular cAMP content. However, antigen challenge of
jejunal segments in which epithelial cells were in contact with sensitized
mast cells increased mucosal cAMP content. These results suggest that
electrogenic Cl- secretion, mediated in part by cAMP, contributes to
antigen-induced jejunal ion transport changes and that histamine and
prostaglandins are involved in eliciting these epithelial responses.
