Effect of bombesin antagonist D-Phe6-BN(6-13)OMe on vagally induced gastrin release from perfused rat stomach.
The aim of the present study was to evaluate the effect of the bombesin antagonist D-Phe6-BN(6-13)OMe (BN-antagonist) on vagally stimulated gastrin release from the isolated rat stomach, which was perfused via the celiac artery with Krebs-Ringer buffer. Vagal stimulation was performed for 10 minutes with 1 ms, 10 V and 10 or 2 Hz, respectively. Gastrin secretion increased significantly during stimulation with 10 and 2 Hz. BN-antagonist was added to the perfusate at the concentration of 10(-6) M, which induced a significant reduction of vagally stimulated gastrin release at 10 Hz (619 +/- 65 vs. 252 +/- 62 pg/10 min, p < 0.05), but not at 2 Hz (564 +/- 117 vs. 493 +/- 113 pg/10 min, p > 0.05). In contrast, atropine (10(-7) M) reduced significantly the gastrin response at 2 Hz (270 +/- 78 pg/10 min, p < 0.01), but not at 10 Hz (446 +/- 87 pg/10 min, p > 0.05). The combination of BN-antagonist and atropine elicited an inhibition of vagally stimulated gastrin release similar to each substance when given alone. Basal gastrin release was not changed by the BN-antagonist. The present data suggest, that in the rat stomach endogenously released bombesin-related peptides contribute to the noncholinergic stimulation of gastrin release at higher stimulation frequencies (10 Hz), however, bombesin-related peptides are not involved, when lower stimulation frequencies (2 Hz) are employed. At both stimulation frequencies additional mechanisms are activated which are noncholinergic and not related to bombesin peptides.
Weigert
N
N
Department of Internal Medicine II, Technical University of Munich, Germany.
Madaus
S
S
Alexiou
C
C
Schepp
W
W
Li
Y
Y
Coy
D H
DH
Classen
M
M
Schusdziarra
V
V
D000818:Animals; D001839:Bombesin / Q000031:analogs & derivatives* / Q000037:antagonists & inhibitors* / Q000494:pharmacology / Q000502:physiology; D004558:Electric Stimulation; D005753:Gastric Mucosa / Q000378:metabolism; D005755:Gastrins / Q000378:metabolism*; D066298:In Vitro Techniques; D008297:Male; D010446:Peptide Fragments / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar; D013270:Stomach / Q000187:drug effects* / Q000294:innervation; D014630:Vagus Nerve / Q000502:physiology
D005755:Gastrins; D010446:Peptide Fragments; C071101:bombesin (6-13), Phe(6) methyl ester-; D001839:Bombesin