[Calcium, phospholipase C and protein kinase C stimulate prostaglandin secretion of isolated gastric mucosa cells of the human].
We studied PGE2-release from isolated human gastric mucosal cells. Mucosa was obtained at surgery and cells were dispersed by collagenase and pronase. Centrifugation with Percoll yielded a fraction of light density cells (70-75% parietal cells; 2-4% mast cells) revealing maximal rates of PGE2-release. A radioimmunoassay was used to measure PGE2-release into the incubation medium. Calcium ionophore A23187 which aids calcium transport across membranes caused a 3.5-fold increase of PGE2-release; this effect was abolished in calcium-free incubation medium. PGE2-release was also stimulated by phospholipase C (100 mU/ml) which is known to induce phosphoinositol breakdown, as well as by 1-oleyl-2-acetyl-sn-glycerol (OAG; 10 microM) and by 12-O-tetradecanoyl-13-acetate (TPA; 10 microM) which cause direct activation of protein kinase C without preceding induction of phosphoinositol breakdown. The response to TPA was potentiated by A23187. The calmodulin antagonist naphthalene sulfonamide W 7 reduced PGE2-release in response to A23187 and TPA (IC50: 1 microM). Our data indicate that PGE2-release of human gastric mucosal cells is stimulated by calcium influx as well as by indirect (phospholipase C) and direct (OAG, TPA) activation of protein kinase C. Stimulation of PGE2-release involves calmodulin-mediated mechanisms.
D002118:Calcium / Q000502:physiology*; D002478:Cells, Cultured; D015232:Dinoprostone; D005753:Gastric Mucosa / Q000378:metabolism*; D006801:Humans; D011453:Prostaglandins / Q000378:metabolism*; D011458:Prostaglandins E / Q000378:metabolism; D011493:Protein Kinase C / Q000502:physiology*; D010738:Type C Phospholipases / Q000502:physiology*
D011453:Prostaglandins; D011458:Prostaglandins E; D011493:Protein Kinase C; D010738:Type C Phospholipases; D015232:Dinoprostone; D002118:Calcium
Calcium, Phospholipase C und Proteinkinase C stimulieren die Prostaglandin-Sekretion isolierter Magenschleimhautzellen des Menschen.