Effect of Ghrelin on contractility of gastric smooth muscle in guinea pigs and the related mechanism
10.3724/SP.J.1008.2009.00238
- Author:
Yuan TAO
1
Author Information
1. Department of Pathophysiology
- Publication Type:Journal Article
- Keywords:
Gastric myenteric plexus;
Ghrelin;
Growth hormone releasing peptide 6;
Nitric oxide;
Stomach
- From:
Academic Journal of Second Military Medical University
2010;30(3):238-243
- CountryChina
- Language:Chinese
-
Abstract:
Objective: To investigate and compare the influences of Ghrelin and growth hormone releasing peptide 6 (GHRP-6) on the contractility of stomach smooth muscle in guinea pigs, and to study the related mechanism. Methods: The myenteric plexuses of gastric fundus and antrium in guinea pigs were stimulated with electrical field stimulation (EFS) to observe the influence of Ghrelin and GHRP-6 on the contractility of stomach smooth muscle. The influences of N-nitro-L-arginine (L-NNA) and L-Arginine (L-AA) on the effect of Ghrelin and GHRP-6 were studied to disclose the mechanism of the effects of Ghrelin and GHRP-6. Results: The circular muscle tissues of the gastric fundus generated on-relaxations and off-contractions when stimulating myenteric plexuses with 1-16 Hz electrical field; the on-responses induced relaxation could be reduced by L-NNA and the off-contractions induced contraction could be blocked by atropine and guanethidine. In fundic strips, ghrelin and GHRP-6 could decrease the on-response induced relaxation and increase off-response induced contraction of the muscle, with the effect of Ghrelin obviously stronger than that of GHRP-6. L-NNA could increase the effects of Ghrelin and GHRP-6-induced muscle contraction, and L-AA could decrease their effects. In the antral strips, electrical field stimulation of myenteric plexuses led to disappearance of relaxation wave, only leaving off-contractions. Both ghrelin and GHRP-6 could increase that contraction. Conclusion: Both ghrelin and GHRP-6 can promote the contractility of stomach smooth muscle in guinea pigs through stimulating myenteric plexuses of gastric fundus and antrium, which might be related to the NO pathway.
