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Acta Physiologica 2011; Volume 202, Supplement 684
The Joint Conference (FAMÉ 2011) of the LXXVth Meeting of the Hungarian Physiological Society, XVIth Meeting of the Hungarian Society of Anatomists, Experimental Section of the Hungarian Society for Experimental and Clinical Pharmacology and Hungarian Society for Microcirculation and Vascular Biology
6/8/2011-6/11/2011
Pécs, Hungary
ROLE OF CENTRAL NERVOUS SYSTEM IN REGULATION OF GASTRO-INTESTINAL FUNCTIONS: EXPERIMENTAL EVIDENCE ON THE SIGNIFICANT ROLE OF ENDOMORPHIN-2 IN GASTRIC MUCOSAL DEFENSE
Abstract number: O15
Gyires1 K., Zadori1 Z. S., Ronai1 A. Z., Tekes2 K., Nemeth3 J.
Aims:
To analyse central regulation of mucosal protection. It has been shown previously that opioid receptor antagonists inhibited the centrally initiated gastroprotective effect of a2-adrenoceptor agonists, cannabinoids, nociceptin, nocistatin and substance P (SP). The question was raised: which endogenous opioid(s) may be involved in the action and which peripheral mechanism may mediate the mucosal protective effect.
Methods:
For induction of mucosal lesions ethanol ulcer model in the rat was used, the compounds were given intracerebroventricularly (icv.) (10 ml), the anti-serum intracisternally (ic.) (5 ml) 10 min prior to ethanol challenge. Concentration of calcitonin-gene related peptide (CGRP) and somatostatin in gastric mucosa was determined by RIA.
Results:
1.) Ic. injection of endomorphin-2 anti-serum inhibited the gastroprotective effect of the a2-adrenoceptor agonist, clonidine (470 pmol), the non-selective cannabinoid receptor agonist, anandamide (11.5 nmol), the cannabinoid CB1-receptor selective ACEA (arachidonyl-2-chloroethylamide) (1.3 nmol) and SP (18 pmol) given icv. 2.) Endomorphin-2 in the dose range of 0.1–20 pmol exerted gastroprotective effect given icv. 3.) Inhibition of the degradation of endomorphin-2 by diprotin A (1 mmol icv.; inhibitor of dipeptidyl-aminopeptidase IV) also induced mucosal protective effect and it was reversed by endomorphin-2 anti-serum. 4.) The reduced level of CGRP (1.22 ±0.06 vs. 0.62±0.05 fmol/mg) and somatostatin (0.89±0.1 vs. 15.1±0.5 fmol/mg) following ethanol administration was reversed by icv. injection of endomorphin-2 (0.1 pmol) (1.05±0.028 and 14.6±0.047 fmol/mg for CGRP and somatostatin, respectively).
Conclusion:
Endomorphin-2 is likely to have a prominent role in central regulation of gastric mucosal defense, since i.) inhibition of its inactivation induced mucosal protection, ii.) endomorphin-2 immuno-neutralization resulted in inhibition of gastroprotective effect of a2-adrenoceptor agonists, cannabinoids and SP, iii.) icv. injection of endomorphin-2 reversed the ethanol-induced reduction of mucosal CGRP and somatostatin level.
Support:
ETT 341/2009 and OTKA/75965
To cite this abstract, please use the following information:
Acta Physiologica 2011; Volume 202, Supplement 684 :O15