Bombesin stimulation of gastrin release from canine gastrin cells in primary culture.
A method is described for the isolation and short-term culture of canine antral gastrin (G) cells. Tissue was dispersed by enzymes and G cells enriched by elutriation and cultured for 40 h. These cultures contained 12% G cells and less than 2% somatostatin- or serotonin-containing cells. Bombesin (0.001-100 pM) potently stimulated gastrin release from cell cultures in a linear fashion over 2 h. The bombesin-specific monoclonal antibody 2A11 dose-dependently blocked bombesin stimulation. Somatostatin (0.001-1,000 nM) inhibited bombesin-stimulated gastrin release. Antibody to somatostatin (Mab S8) prevented the inhibition by exogenous somatostatin but did not alter bombesin-stimulated or basal gastrin release. The substance P (SP) analogue spantide (1 nM-1 microM) did not inhibit bombesin-stimulated gastrin release. Postreceptor activation of adenylate cyclase by forskolin and of protein kinase C by the phorbol ester, beta-TPA, caused gastrin release. The calcium ionophore A23187 also released gastrin in a dose-dependent fashion. This methodology allows enrichment and short-term culture of antral G cells; these cells have stimulatory bombesin and inhibitory somatostatin receptors, suggesting that these peptides have a direct action on antral G cells. Furthermore, G cells are activated by cAMP and calcium/phosphatidylinositol-dependent mechanisms.
D000262:Adenylyl Cyclases / Q000378:metabolism; D000818:Animals; D001839:Bombesin / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D000001:Calcimycin / Q000494:pharmacology; D002478:Cells, Cultured; D005576:Colforsin / Q000494:pharmacology; D004285:Dogs; D005750:Gastric Juice / Q000378:metabolism*; D005753:Gastric Mucosa / Q000378:metabolism; D005755:Gastrins / Q000378:metabolism*; D011493:Protein Kinase C / Q000378:metabolism; D018004:Receptors, Bombesin; D017981:Receptors, Neurotransmitter / Q000502:physiology; D012636:Secretory Rate / Q000187:drug effects; D013004:Somatostatin / Q000494:pharmacology; D013373:Substance P / Q000031:analogs & derivatives / Q000494:pharmacology; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology
D005755:Gastrins; D018004:Receptors, Bombesin; D017981:Receptors, Neurotransmitter; D005576:Colforsin; D013373:Substance P; D000001:Calcimycin; D013004:Somatostatin; C042867:spantide; D011493:Protein Kinase C; D000262:Adenylyl Cyclases; D013755:Tetradecanoylphorbol Acetate; D001839:Bombesin