AJP - Gastrointestinal and Liver Physiology, Vol 248, Issue 4 456-G462, Copyright © 1985 by American Physiological Society
Inhibition of neurally mediated gastrin secretion by bombesin antiserum
M. L. Schubert, B. Saffouri, J. H. Walsh and G. M. Makhlouf
In vitro studies on the vascularly perfused rat stomach have shown that
gastrin secretion is regulated by intramural cholinergic and noncholinergic
neurons. We have postulated that bombesin (gastrin-releasing peptide), a
known gastrin stimulant present in antral mucosal nerve fibers, is the most
likely candidate for noncholinergic transmitter. Bombesin antiserum (final
dilution, 1:150) but not control serum added to the vascular perfusate
inhibited the gastrin response to 1,1-dimethyl-4-phenylpiperazinium by 59
+/- 17% (P less than 0.01) and to electrical field stimulation by 60 +/-
16% (P less than 0.01), and its effect was additive to that of 10(-7) M
atropine (75-94%), thus accounting for the greater part of neurally induced
gastrin secretion. The effects of atropine and bombesin antiserum on
somatostatin secretion were consistent also with blockade of cholinergic
and noncholinergic neurons, respectively. The results indicate that
bombesin and acetylcholine are the main intramural neural regulators of
gastrin and somatostatin secretion. Acetylcholine acts predominantly to
decrease the paracrine secretion of somatostatin, thereby eliminating the
continuous restraint of somatostatin on gastrin secretion and enabling
bombesin to exert its potent stimulatory effect on gastrin secretion.
