Regulation of mucus secretion by cells isolated from the rat gastric mucosa.

Abstract

SUMMARY1. A suspension of cells, containing about 30 % mucous cells, was isolated from the rat fundic mucosa, and was pre-incubated with D-[6-311]glucosamine. 3H-labelled material subsequently released into the medium was separated by Fast Protein Liquid Chromatography on a Superose 6 column.2. A sharp peak of labelled high molecular weight material eluted from the column close to the void volume. This material was identified as mucous glycoprotein by its similar chromatographic behaviour to partially purified rat gastric mucous glycoprotein, by its resistance to complete degradation by papain and by its behaviour on treatment with dithiothreitol. On a caesium chloride density gradient the labelled material was virtually all located between densities of 1t35 and 1-53 g/ml, with the main peak at 1-40 g/ml.3. A broad peak of lower molecular weight material was also eluted from the column. The release of this unidentified material did not seem to be closely associated with the release of mucous glycoprotein from the cells.4. Release of mucous glycoprotein was stimulated by secretin (half-maximally effective concentration 2-a nM, 84% stimulation above basal release at 100 nM), and by isoprenaline (half-maximally effective concentration 34 nm, 33 % stimulation at 1 tM). Carbachol (0-5 mM) produced a significant (18-29%) stimulation of mucus secretion, but gastrin (100 nM), histamine (0-5 mM) and epidermal growth factor (200 nM) were without effect.5. The preparation should prove useful in the identification of the agents which regulate gastric mucus secretion.

Insulin Stimulates Production of Glycoconjugate Layers on the Cell Surface of Gastric Surface Mucous Cell Line GSM06

“…This finding supports previous results obtained using isolated rat cells [2]. In contrast, EGF has been shown to stimulate synthesis and secretion of mucus glycoproteins in human gastric mucosa [14] and primary culture of rabbit mucosal cells [13].…”

“…Even in in vitro studies, the effects of the major acid secretagogues remain controver sial [2][3][4][15][16][17]. Although the reason is unclear, these discrepancies may reflect species differences or experi mental conditions.…”

The Prostanoid EP4 Receptor and Its Signaling Pathway

“…Similarly, EP4-mediated increases in mucus secretion and intestinal fluid secretion have been found to contribute to the process of intestinal ulcer healing (Kunikata et al, 2002). It has also been reported that cAMP contributes to gastrointestinal mucin secretion, including its principal functional component, mucus glycoprotein (Keates and Hanson, 1990;Słomiany and Słomiany, 2005). Słomiany and Słomiany (2005) demonstrated that b-adrenergic GPCR activation and subsequent AC activation triggered mucin secretion via both the PKA and PI3K pathways.…”

Activation of Ca(2+)-dependent K+ current by acetylcholine and histamine in a human gastric epithelial cell line.

“…Therefore, in the ACh response, this positive feedback mechanism could effectively be activated. This may explain the former report that ACh is much more effective than His in mucin secretion and cell proliferation (Keates and Hanson, 1990;McCool et al, 1990).…”