title: Biochemical mechanisms of regulation of mucus secretion by prostaglandin E2 in rat gastric mucosa.
abstract: The effects of prostaglandin E2 (PGE2) and inhibitors of RNA and protein synthesis on rat gastric mucosa were investigated in order to study the cellular and biochemical mechanisms involved in the PGE2-stimulated formation and secretion of gastric mucus. It was shown that PGE2 caused significant stimulation of gastric mucus secretion and this effect of PGE2 was inhibited by cycloheximide but not actinomycin D. The influence of PGE2 on the in vitro incorporation of N-acetyl-[3H]glucosamine and 14C-labelled amino acids in to the glycoproteins representing a major mucus component of the isolated gastric mucosa cells was also studied. The stimulatory effect of PGE2 on incorporation of labelled precursors into glycoproteins of gastric cells was also inhibited by cycloheximide. These results suggest that the effect of PGE2 on mucus production requires ongoing protein synthesis. cAMP can fully reproduce the effect of PGE2 on the formation and the secretion of gastric mucus. The binding of [3H]PGE2 to rat gastric non-parietal cell fractions consisting predominantly of mucoid cells correlated with the ability of PGE2 to increase adenylate cyclase activity in these cells. PGE2 had no effect on adenylate cyclase activity in cell suspensions enriched in parietal cells. These data suggest further that the stimulatory effect of PGE2 on mucus secretion may be mediated by cAMP as a messenger.
mesh_terms: D000262:Adenylyl Cyclases / Q000378:metabolism; D000818:Animals; D000242:Cyclic AMP / Q000494:pharmacology; D003513:Cycloheximide / Q000494:pharmacology; D015232:Dinoprostone; D005753:Gastric Mucosa / Q000166:cytology / Q000378:metabolism*; D006023:Glycoproteins / Q000096:biosynthesis; D066298:In Vitro Techniques; D007202:Indicators and Reagents; D008297:Male; D009093:Mucus / Q000378:metabolism*; D011458:Prostaglandins E / Q000502:physiology*; D051381:Rats; D011919:Rats, Inbred Strains; D013806:Theophylline / Q000494:pharmacology
chemical_list: D006023:Glycoproteins; D007202:Indicators and Reagents; D011458:Prostaglandins E; D003513:Cycloheximide; D013806:Theophylline; D000242:Cyclic AMP; D000262:Adenylyl Cyclases; D015232:Dinoprostone