Cyclic AMP and Ca²⁺ interactions affecting epithelial chloride secretion in human cultured colonic epithelia

Abstract

monolayers as these agonists increase cyclic AMP via eicosanoid production.

Calcitonin gene‐related peptide receptors in human gastrointestinal epithelia

“…The electrogenic secretory responses to ra-CGRP in the present study were not significantly altered by pretreating either cell line with the cyclo-oxygenase inhibitor piroxicam at a concentration which inhibits secretagogue-induced (in the same cell lines; MacVinish et al, 1993) and basal secretion in other gastrointestinal epithelial preparations (Cox & Cuthbert, 1988;Ferrar et al, 1990). Thus, the absence of piroxicam sensitivity in HCA-7 and Col-29 indicates that eicosanoid production is not involved in CGRP responses in these epithelia.…”

“…Thus, the absence of piroxicam sensitivity in HCA-7 and Col-29 indicates that eicosanoid production is not involved in CGRP responses in these epithelia. In contrast, the secretory response stimulated in Col-29 cells by lysylbradykinin (MacVinish et al, 1993) is mediated by both a Ca2"-and prostaglandin-dependent mechanism, the latter providing for cAMP-mediated Clsecretion. In our studies pretreatment with the anti-secretory neuropeptide, somatostatin also failed to have any significant effect upon ra-CGRP-mediated ion secretion in either cell line, whereas in rat colonic mucosa somatostatin inhibits raand rp-CGRP-mediated secretion (Ferrar et al, 1990).…”

“…In order to study epithelial CGRP receptors in the absence of other mucosal cell types we have used two adenocarcinoma cell lines which, when grown to confluence on permeable supports, respond to a range of secretory (Cuthbert et al, 1987;MacVinish et al, 1993) and antisecretory (H.M. Cox, unpublished observations) agonists. The two ' Author for correspondence.…”

Inhibition of human colon cancer cell growth by selective inhibition of cyclooxygenase-2.

“…Both HCA-7 and HCT-116 cell lines were originally derived from human colonic carcinomas (23,24). The HCA-7 cells were derived by Kirkland and co-workers in the United Kingdom and have been extensively characterized (23,(25)(26)(27)(28)(29). Recent work by our group has shown that the HCA-7 cells become polarized in culture and release prostaglandins in a vectorial fashion (30).…”

Carbachol-stimulated chloride secretion in mouse colon: evidence of a role for autocrine prostaglandin E2 release

“…However, there is evidence for epithelial PGEµ release, and COX_1 and COX_2 are present in native intestinal epithelia (Cohn et al 1997) and intestinal cell lines (Dubois et al 1994;Hinterleitner et al 1996;Eckmann et al 1997). Furthermore, colonic cell lines (T84, HT29) secrete PGs, and exhibit indomethacin-sensitive Cl¦ secretion (MacVinish et al 1993). The existence and functional significance of autocrine PG release in the native colon has not been adequately addressed.…”