Bombesin inhibits histamine release from the rat oxyntic mucosa by a somatostatin-dependent mechanism.
METHODS
This study examines the effect of bombesin on endogenous somatostatin and the histamine-synthesizing enterochromaffin-like cells. Somatostatin and histamine were measured in the venous effluent of isolated/antrectomized vascularly perfused rat stomachs after administration of bombesin and gastrin alone or combined. Histidine decarboxylase (HDC) enzyme activity and mRNA abundance were measured in the gastric corpus after intravenous administration of bombesin to conscious rats.


RESULTS
Bombesin released somatostatin from the isolated stomachs and reduced basal and gastrin-stimulated venous histamine. Somatostatin antiserum partially reversed the effect of bombesin on basal and gastrin-stimulated histamine release. In conscious fed rats, intravenous bombesin doubled serum gastrin concentrations and increased HDC activity.


CONCLUSIONS
We conclude that endogenous (paracrine) somatostatin inhibits basal and gastrin-stimulated histamine release from the ECL cell. In intact animals this effect is surmountable by simultaneously released gastrin, suggesting that a balance between the effects of gastrin and somatostatin determines the activation of the ECL cell.
Sandvik
A K
AK
Physiological Laboratory, University School of Medicine, Trondheim, Norway.
Brenna
E
E
Sundan
A
A
Holst
J J
JJ
Waldum
H I
HI
D000818:Animals; D015152:Blotting, Northern; D001839:Bombesin / Q000008:administration & dosage / Q000493:pharmacokinetics / Q000494:pharmacology*; D005743:Gastrectomy; D005755:Gastrins / Q000097:blood; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases / Q000235:genetics; D006632:Histamine / Q000097:blood; D006636:Histamine Release / Q000187:drug effects*; D006640:Histidine Decarboxylase / Q000235:genetics / Q000378:metabolism; D066298:In Vitro Techniques; D007262:Infusions, Intravenous; D008297:Male; D010295:Parietal Cells, Gastric / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism*; D010477:Perfusion; D016133:Polymerase Chain Reaction; D011706:Pyloric Antrum / Q000601:surgery; D012333:RNA, Messenger / Q000032:analysis; D011863:Radioimmunoassay; D051381:Rats; D017208:Rats, Wistar; D013004:Somatostatin / Q000097:blood / Q000378:metabolism*
D005755:Gastrins; D012333:RNA, Messenger; D013004:Somatostatin; D006632:Histamine; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases; D006640:Histidine Decarboxylase; D001839:Bombesin