Beta-adrenergic stimulation of gastrin release mediated by gastrin-releasing peptide in rat antral mucosa.
The present studies were directed to examine the effects of beta-adrenergic and cholinergic stimulation on gastrin release and to assess the potential role of gastrin-releasing peptide in exerting these effects, utilizing incubated rat antral mucosa. Rat antral mucosa was incubated at 37 degrees C in Krebs-Henseleit bicarbonate buffer, pH 7.4, continuously gassed with 95% O2-5% CO2. After 1 h media were sampled for radioimmunoassay measurement of gastrin content. Inclusion of carbachol (2.5 X 10(-6) M) in culture medium increased medium gastrin concentration by 106 +/- 28% (P less than 0.01); addition of specific antibodies to gastrin-releasing peptide to the culture medium did not affect carbachol-stimulated gastrin release. Inclusion of isoproterenol (10(-9) M) in culture medium did not affect somatostatin release into the medium, but increased medium gastrin by 234 +/- 24% (P less than 0.001). However, in contrast to carbachol, addition of antibodies to gastrin-releasing peptide to culture medium decreased isoproterenol-stimulated gastrin release by 67 +/- 9% (P less than 0.001). Results of these studies indicate that, under the conditions of these experiments, beta-adrenergic, but not muscarinic, stimulation of gastrin release may be mediated, at least in part, through gastrin-releasing peptide.
D000818:Animals; D002217:Carbachol / Q000494:pharmacology*; D003470:Culture Media; D004305:Dose-Response Relationship, Drug; D005753:Gastric Mucosa / Q000378:metabolism*; D019886:Gastrin-Releasing Peptide; D005755:Gastrins / Q000378:metabolism*; D007545:Isoproterenol / Q000494:pharmacology*; D008297:Male; D010455:Peptides / Q000502:physiology*; D051381:Rats; D011919:Rats, Inbred Strains; D013004:Somatostatin / Q000502:physiology
D003470:Culture Media; D005755:Gastrins; D010455:Peptides; D013004:Somatostatin; D019886:Gastrin-Releasing Peptide; D002217:Carbachol; D007545:Isoproterenol