Skip to main page content
Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
, 270 (6 Pt 1), G1001-9

Role of 5-HT in Cholera Toxin-Induced Mucin Secretion in the Rat Small Intestine


Role of 5-HT in Cholera Toxin-Induced Mucin Secretion in the Rat Small Intestine

B A Moore et al. Am J Physiol.


We examined the role of 5-hydroxytryptamine (5-HT) in cholera toxin (CT)-induced mucin secretion in the proximal and distal regions of the rat small intestine. Neither the 5-HT2 receptor antagonist ketanserin nor the cyclooxygenase inhibitor indomethacin was capable of inhibiting choleraic mucin secretion. However, in the presence of the mixed 5-HT3/4 receptor antagonist tropisetron at doses that block both receptor subtypes, the secretory response was reduced to baseline levels in the proximal and distal small intestine. The selective 5-HT3 receptor antagonist ondansetron had no significant effect. These findings suggest that choleraic mucin secretion is mediated primarily through the activation of a 5-HT4-like receptor. Mucin secretion in response to the exogenous application of 5-HT occurs via two pathways: one is mediated by a 5-HT4-like receptor and is capsaicin sensitive but tetrodotoxin (TTX) insensitive, and one lacks the capsaicin-sensitive 5-HT4-mediated response but is TTX sensitive. Both converge on a common pathway that is cholinergic. No significant differences were observed between proximal and distal intestinal segments.

Similar articles

See all similar articles

Cited by 10 PubMed Central articles

See all "Cited by" articles

Publication types

LinkOut - more resources