Helicobacter pylori fatty acid cis 9,10-methyleneoctadecanoic acid increases [Ca2+]i, activates protein kinase C and stimulates acid secretion in parietal cells.
The effect of the Helicobacter pylori (H. pylori) fatty acid cis 9,10-methyleneoctadecanoic acid (MOA) on gastric acid secretion was studied in isolated guinea-pig parietal cells. MOA (1 and 3 micromol/l) stimulated basal and enhanced histamine- and dibutyryl cyclic AMP-stimulated acid secretion in parietal cells. MOA increased intracellular free [Ca2+]i concentration in a concentration-dependent manner. The source of [Ca2+]i was extracellular as demonstrated by depletion of [Ca2+]i with EGTA. Furthermore, MOA caused activation of parietal cell protein kinase C (PKC). The effect of MOA upon PKC activation was [Ca2+]i-dependent but did not require phosphatidylserine as phospholipid co-factor. Similarly to the effect of diolein, MOA increased the stimulatory effect of phosphatidylserine at low [Ca2+]i concentrations. Treatment of parietal cells with MOA caused translocation of PKC from the cytosol to the membrane-associated cell fraction. We propose that MOA stimulates parietal cell acid secretion presumably by an increase of cytosolic free [Ca2+]i concentrations and PKC activation.
Department of General Pharmacology, Hannover Medical School, Germany.
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Beil
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Birkholz
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Wagner
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Sewing
D015056:1-Methyl-3-isobutylxanthine / Q000494:pharmacology; D000632:Aminopyrine / Q000378:metabolism; D000818:Animals; D003994:Bucladesine / Q000494:pharmacology; D020013:Calcium Signaling / Q000187:drug effects*; D002217:Carbachol / Q000494:pharmacology; D004075:Diglycerides / Q000494:pharmacology; D004789:Enzyme Activation; D005227:Fatty Acids / Q000032:analysis / Q000494:pharmacology*; D005744:Gastric Acid / Q000378:metabolism*; D006168:Guinea Pigs; D016480:Helicobacter pylori / Q000737:chemistry*; D006632:Histamine / Q000494:pharmacology; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D010295:Parietal Cells, Gastric / Q000187:drug effects / Q000378:metabolism* / Q000382:microbiology; D010718:Phosphatidylserines / Q000494:pharmacology; D010726:Phosphodiesterase Inhibitors / Q000494:pharmacology; D011493:Protein Kinase C / Q000037:antagonists & inhibitors / Q000378:metabolism*; D019311:Staurosporine / Q000494:pharmacology
D004075:Diglycerides; D005227:Fatty Acids; D010718:Phosphatidylserines; D010726:Phosphodiesterase Inhibitors; D000632:Aminopyrine; C029355:dihydrosterculic acid; D003994:Bucladesine; D006632:Histamine; D002217:Carbachol; D007770:L-Lactate Dehydrogenase; D011493:Protein Kinase C; D019311:Staurosporine; D015056:1-Methyl-3-isobutylxanthine; C013965:diolein