Stimulation of gastrin release by bombesin and canine gastrin-releasing peptides. Studies with isolated canine G cells in primary culture.
Bombesin, a polypeptide derived from frog skin, has been shown to stimulate gastrin release from the gastric antrum in vivo and in vitro. To elucidate the mechanisms of this effect, we developed a method to culture isolated and enriched G cells from canine stomach. After digestion of antral mucosa with collagenase and EDTA, dispersed cells were fractionated by counterflow elutriation then cultured on a collagen support. Bombesin and three molecular forms of canine gastrin-releasing peptides all stimulated gastrin release from G cells in a dose-dependent manner. The effect of bombesin was suppressed by somatostatin and potentiated by dibutyryl cyclic AMP (10(-3) M) but not by carbachol (10(-6) M). Extracellular calcium depletion attenuated the stimulation of gastrin release by bombesin but not by forskolin. These findings suggest that the bombesin family peptides directly activate G cells through calcium-dependent mechanisms to cause gastrin release.
D000818:Animals; D001839:Bombesin / Q000494:pharmacology*; D003994:Bucladesine / Q000494:pharmacology; D002118:Calcium / Q000502:physiology; D002478:Cells, Cultured; D005576:Colforsin / Q000494:pharmacology; D004285:Dogs; D005753:Gastric Mucosa / Q000187:drug effects / Q000378:metabolism*; D019886:Gastrin-Releasing Peptide; D005755:Gastrins / Q000378:metabolism*; D010455:Peptides / Q000494:pharmacology*; D011706:Pyloric Antrum / Q000378:metabolism; D013004:Somatostatin / Q000494:pharmacology
D005755:Gastrins; D010455:Peptides; D005576:Colforsin; D013004:Somatostatin; D003994:Bucladesine; D019886:Gastrin-Releasing Peptide; D001839:Bombesin; D002118:Calcium