TY - JOUR

T1 - Effect of calcitonin gene-related peptide (CGRP) on motility and on the release of substance P, neurokinin A, somatostatin and gastrin in the isolated perfused porcine antrum

AU - Rasmussen, T N

AU - Schmidt, P

AU - Poulsen, S S

AU - Holst, J J

AU - Poulsen, Steen Seier

PY - 2001/8/1

Y1 - 2001/8/1

N2 - We studied the effect of porcine CGRP (pCGRP) in concentrations from 10(-10) to 10(-8) mol L(-1) on the motility and on the release of substance P, neurokinin A, somatostatin and gastrin in the antrum using the isolated perfused porcine antrum as experimental model. In addition, we studied the localization of CGRP by immunohistochemistry in the porcine antrum. CGRP-immunoreactive nerve fibres were found mainly in the submucous layer and in the external muscle coat, where they were seen in all layers, and in the ganglia of the myenteric nervous plexus. The frequency of contraction was significantly and dose-dependently increased from a basal level of 11.8 +/- 0.5 contractions per 5 min to 24.4 +/- 3.6 contractions per 5 min at pCGRP 10(-8) mol L(-1). At this dose, the release of substance P and neurokinin A was significantly increased to 470 +/- 149% and 217 +/- 26%, respectively, compared to basal release. The effect of pCGRP was unaffected by the addition of the nonpeptide antagonists for the NK-1 (CP-99994) and NK-2 receptors (SR48968), both at 10(-6) mol L(-1), whereas atropine (10(-6) mol L(-1)) completely abolished the motor effect of pCGRP. The release of somatostatin was significantly increased by 154 +/- 15% in response to CGRP at 10(-8) mol L(-1). The release of gastrin was unaffected by pCGRP. In conclusion, pCGRP increases contractile activity in the porcine antrum, an effect that involves cholinergic mechanisms but is independent of the release of substance P and neurokinin A. in addition, pCGRP increases the release of somatostatin but has no effect on gastrin release in the isolated perfused porcine antrum.

AB - We studied the effect of porcine CGRP (pCGRP) in concentrations from 10(-10) to 10(-8) mol L(-1) on the motility and on the release of substance P, neurokinin A, somatostatin and gastrin in the antrum using the isolated perfused porcine antrum as experimental model. In addition, we studied the localization of CGRP by immunohistochemistry in the porcine antrum. CGRP-immunoreactive nerve fibres were found mainly in the submucous layer and in the external muscle coat, where they were seen in all layers, and in the ganglia of the myenteric nervous plexus. The frequency of contraction was significantly and dose-dependently increased from a basal level of 11.8 +/- 0.5 contractions per 5 min to 24.4 +/- 3.6 contractions per 5 min at pCGRP 10(-8) mol L(-1). At this dose, the release of substance P and neurokinin A was significantly increased to 470 +/- 149% and 217 +/- 26%, respectively, compared to basal release. The effect of pCGRP was unaffected by the addition of the nonpeptide antagonists for the NK-1 (CP-99994) and NK-2 receptors (SR48968), both at 10(-6) mol L(-1), whereas atropine (10(-6) mol L(-1)) completely abolished the motor effect of pCGRP. The release of somatostatin was significantly increased by 154 +/- 15% in response to CGRP at 10(-8) mol L(-1). The release of gastrin was unaffected by pCGRP. In conclusion, pCGRP increases contractile activity in the porcine antrum, an effect that involves cholinergic mechanisms but is independent of the release of substance P and neurokinin A. in addition, pCGRP increases the release of somatostatin but has no effect on gastrin release in the isolated perfused porcine antrum.

KW - Animals

KW - Calcitonin Gene-Related Peptide

KW - Gastrins

KW - Gastrointestinal Motility

KW - Immunohistochemistry

KW - Neurokinin A

KW - Perfusion

KW - Pyloric Antrum

KW - Somatostatin

KW - Substance P

KW - Swine

M3 - Journal article

C2 - 11576394

VL - 13

SP - 353

EP - 359

JO - Neurogastroenterology and Motility

JF - Neurogastroenterology and Motility

SN - 1350-1925

IS - 4

ER -