Gastrin-releasing peptide stimulates cholecystokinin secretion in perfused rat duodenum.
We examined the effect of porcine gastrin-releasing peptide (GRP-27) and other analogous neuropeptides on cholecystokinin (CCK) secretion from the isolated perfused rat duodenum. GRP-27 stimulated CCK secretion in a monophasic pattern and in a dose-dependent manner ranging from 10(-9) M to 10(-6) M, and 10(-7) M of GRP-27 led to an increment of 442 +/- 120.8 fmol/3 min. The stimulatory effect of GRP-27 on CCK was not inhibited by 10(-5) M of atropine. 10(-7) M of neuromedin C and B, analogs of GRP, stimulated CCK secretion to increments of 382 +/- 64.1 and 289 +/- 47.2 fmol/3 min, respectively. Carbachol (10(-9) to 10(-6) M), VIP (10(-9)M), secretin (10(-9)M) and glucose (11 mM) did not stimulate CCK secretion, and the addition of atropine (10(-5)M) to them led to no significant changes. These results suggest that GRP may directly stimulate CCK secretion from the duodenum and work as a non-cholinergic, peptidergic neurotransmitter.
Nakano
I
I
Third Department of Internal Medicine, Kyushu University, Fukuoka, Japan.
Miyazaki
K
K
Funakoshi
A
A
Tateishi
K
K
Hamaoka
T
T
Yajima
H
H
D000818:Animals; D001839:Bombesin / Q000494:pharmacology; D002217:Carbachol / Q000494:pharmacology; D002766:Cholecystokinin / Q000378:metabolism*; D004386:Duodenum / Q000378:metabolism*; D019886:Gastrin-Releasing Peptide; D005947:Glucose / Q000494:pharmacology; D066298:In Vitro Techniques; D007419:Intestinal Secretions / Q000378:metabolism*; D008297:Male; D015287:Neurokinin B / Q000031:analogs & derivatives / Q000494:pharmacology; D010446:Peptide Fragments / Q000494:pharmacology; D010455:Peptides / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains; D012633:Secretin / Q000494:pharmacology
D010446:Peptide Fragments; D010455:Peptides; D012633:Secretin; D019886:Gastrin-Releasing Peptide; C040794:neuromedin C; D015287:Neurokinin B; C038393:neuromedin B; D002217:Carbachol; D002766:Cholecystokinin; D005947:Glucose; D001839:Bombesin