Relationship between inositol 1,4,5-trisphosphate mass level and [14C]aminopyrine uptake in gastrin-stimulated parietal cells.
The relationship between gastrin-stimulated inositol 1,4,5-trisphosphate (Ins(1,4,5)P3) content and [14C]aminopyrine ([14C]AP) uptake (an index of in vitro acid secretion) was investigated in a population of highly enriched rabbit parietal cells (90 +/- 5%). Gastrin induced a rapid rise in Ins(1,4,5)P3 content which was maximal within 15 s of stimulation (2- to 2.5-fold basal level) followed by a rapid decrease within 30 s; a high Ins(1,4,5)P3 level could also be observed after a longer time of hormone stimulation (180 s). Gastrin dose-dependently induced Ins(1,4,5)P3 accumulation and [14C]AP uptake; both dose-response curves were similar (EC50 approximately 0.1 nM). Furthermore, L-365,260 (3-(acylamino)benzodiazepine), a selective gastrin/CCK-B receptor antagonist, dose-dependently inhibited Ins(1,4,5)P3 production and [14C]AP accumulation induced by 10 nM gastrin with a similar potency (IC50 approximately 1-2 nM). These results led us to conclude that Ins(1,4,5)P3 is involved in gastrin-stimulated acid secretory activity of gastric parietal cells.
Roche
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S
Laboratoire de Biochimie des Membranes, CNRS UPR-8402 - INSERM U-249, Faculté de Pharmacie, Montpellier, France.
Gusdinar
T
T
Bali
J P
JP
Magous
R
R
D000632:Aminopyrine / Q000378:metabolism*; D000818:Animals; D001570:Benzodiazepinones / Q000494:pharmacology; D005744:Gastric Acid / Q000378:metabolism; D005755:Gastrins / Q000502:physiology*; D066298:In Vitro Techniques; D015544:Inositol 1,4,5-Trisphosphate / Q000378:metabolism*; D007700:Kinetics; D010295:Parietal Cells, Gastric / Q000378:metabolism*; D010671:Phenylurea Compounds; D011817:Rabbits
D001570:Benzodiazepinones; D005755:Gastrins; D010671:Phenylurea Compounds; D000632:Aminopyrine; C058121:L 365260; D015544:Inositol 1,4,5-Trisphosphate