Effect of cionin on histamine and acid secretion by the perfused rat stomach.
BACKGROUND
The protochordean octapeptide cionin is structurally a hybrid of mammalian cholecystokinin (CCK) and gastrin. An earlier study has shown that cionin in mammals stimulates gallbladder contraction and gastric somatostatin release, similarly to CCK-8.


METHODS
In the present study we examined the effect of cionin on histamine release and acid secretion of the stomach, both effects being mediated by CCK-B/gastrin receptors.


RESULTS
Cionin induced a concentration-dependent increase in histamine release and acid secretion in the isolated, vascularly perfused rat stomach, detectable at a concentration of 4 pM and reaching a maximum at a concentration of 512 pM. The CCK-B/gastrin receptor antagonist L 365,260 abolished the stimulating effect of cionin on both histamine release and acid secretion, whereas the CCK-A receptor antagonist L 364,718 only had a faint effect.


CONCLUSIONS
Cionin is a potent and efficient stimulator of gastric histamine release and acid secretion interacting via a CCK-B receptor.
Mårvik
R
R
Dept. of Surgery, Trondheim University Hospital, Norway.
Johnsen
A H
AH
Rehfeld
J F
JF
Sandvik
A
A
Waldum
H L
HL
D000595:Amino Acid Sequence; D000818:Animals; D001570:Benzodiazepinones / Q000494:pharmacology; D005744:Gastric Acid / Q000378:metabolism*; D005753:Gastric Mucosa / Q000378:metabolism*; D006636:Histamine Release / Q000187:drug effects*; D066298:In Vitro Techniques; D008297:Male; D008969:Molecular Sequence Data; D009479:Neuropeptides / Q000494:pharmacology*; D010671:Phenylurea Compounds; D051381:Rats; D017208:Rats, Wistar; D011949:Receptors, Cholecystokinin / Q000037:antagonists & inhibitors
D001570:Benzodiazepinones; D009479:Neuropeptides; D010671:Phenylurea Compounds; D011949:Receptors, Cholecystokinin; C063059:cionin; C058121:L 365260