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Evidence for a modulatory role of orexin A on the nitrergic neurotransmission in the mouse gastric fundus.
Regul Pept. 2009 Apr 10; 154(1-3):54-9.RP

Abstract

The presence of orexins and their receptors in the gastrointestinal tract supports a local action of these peptides. Aim of the present study was to investigate the effects of orexin A (OXA) on the relaxant responses of the mouse gastric fundus. Mechanical responses of gastric strips were recorded via force-displacement transducers. The presence of orexin receptors (OX-1R) was also evaluated by immunocytochemistry. In carbachol precontracted strips and in the presence of guanethidine, electrical field stimulation (EFS) elicited a fast inhibitory response that may be followed, at the highest stimulation frequencies employed, by a sustained relaxation. All relaxant responses were abolished by TTX. The fast response was abolished by the nitric oxide (NO) synthesis inhibitor l-NNA (2x10(-4) M) as well as by the guanylate cyclase inhibitor ODQ (1x10(-6) M). OXA (3x10(-7) M) greatly increased the amplitude of the EFS-induced fast relaxation without affecting the sustained one. OXA also potentiated the amplitude of the relaxant responses elicited by the ganglionic stimulating agent DMPP (1x10(-5) M), but had no effects on the direct smooth muscle relaxant responses elicited by papaverine (1x10(-5) M) or VIP (1x10(-7) M). In the presence of l-NNA, the response to DMPP was reduced in amplitude and no longer influenced by OXA. The OX1 receptor antagonist SB-334867 (1x10(-5) M) reduced the amplitude of the EFS-induced fast relaxation without influencing neither the sustained responses nor those to papaverine and VIP. Immunocytochemistry showed the presence of neurons that co-express neuronal nitric oxide synthase and OX-1R. These results indicate that, in mouse gastric fundus, OXA exerts a modulatory action at the postganglionic level on the nitrergic neurotransmission.

Authors+Show Affiliations

Department of Physiological Sciences, University of Florence, Florence, Italy. mcaterina.baccari@unifi.itNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

19150469

Citation

Baccari, Maria Caterina, et al. "Evidence for a Modulatory Role of Orexin a On the Nitrergic Neurotransmission in the Mouse Gastric Fundus." Regulatory Peptides, vol. 154, no. 1-3, 2009, pp. 54-9.
Baccari MC, Bani D, Calamai F. Evidence for a modulatory role of orexin A on the nitrergic neurotransmission in the mouse gastric fundus. Regul Pept. 2009;154(1-3):54-9.
Baccari, M. C., Bani, D., & Calamai, F. (2009). Evidence for a modulatory role of orexin A on the nitrergic neurotransmission in the mouse gastric fundus. Regulatory Peptides, 154(1-3), 54-9. https://doi.org/10.1016/j.regpep.2008.12.005
Baccari MC, Bani D, Calamai F. Evidence for a Modulatory Role of Orexin a On the Nitrergic Neurotransmission in the Mouse Gastric Fundus. Regul Pept. 2009 Apr 10;154(1-3):54-9. PubMed PMID: 19150469.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Evidence for a modulatory role of orexin A on the nitrergic neurotransmission in the mouse gastric fundus. AU - Baccari,Maria Caterina, AU - Bani,Daniele, AU - Calamai,Franco, Y1 - 2008/12/31/ PY - 2008/07/29/received PY - 2008/11/12/revised PY - 2008/12/15/accepted PY - 2009/1/20/entrez PY - 2009/1/20/pubmed PY - 2009/6/23/medline SP - 54 EP - 9 JF - Regulatory peptides JO - Regul. Pept. VL - 154 IS - 1-3 N2 - The presence of orexins and their receptors in the gastrointestinal tract supports a local action of these peptides. Aim of the present study was to investigate the effects of orexin A (OXA) on the relaxant responses of the mouse gastric fundus. Mechanical responses of gastric strips were recorded via force-displacement transducers. The presence of orexin receptors (OX-1R) was also evaluated by immunocytochemistry. In carbachol precontracted strips and in the presence of guanethidine, electrical field stimulation (EFS) elicited a fast inhibitory response that may be followed, at the highest stimulation frequencies employed, by a sustained relaxation. All relaxant responses were abolished by TTX. The fast response was abolished by the nitric oxide (NO) synthesis inhibitor l-NNA (2x10(-4) M) as well as by the guanylate cyclase inhibitor ODQ (1x10(-6) M). OXA (3x10(-7) M) greatly increased the amplitude of the EFS-induced fast relaxation without affecting the sustained one. OXA also potentiated the amplitude of the relaxant responses elicited by the ganglionic stimulating agent DMPP (1x10(-5) M), but had no effects on the direct smooth muscle relaxant responses elicited by papaverine (1x10(-5) M) or VIP (1x10(-7) M). In the presence of l-NNA, the response to DMPP was reduced in amplitude and no longer influenced by OXA. The OX1 receptor antagonist SB-334867 (1x10(-5) M) reduced the amplitude of the EFS-induced fast relaxation without influencing neither the sustained responses nor those to papaverine and VIP. Immunocytochemistry showed the presence of neurons that co-express neuronal nitric oxide synthase and OX-1R. These results indicate that, in mouse gastric fundus, OXA exerts a modulatory action at the postganglionic level on the nitrergic neurotransmission. SN - 0167-0115 UR - https://www.unboundmedicine.com/medline/citation/19150469/Evidence_for_a_modulatory_role_of_orexin_A_on_the_nitrergic_neurotransmission_in_the_mouse_gastric_fundus_ L2 - https://linkinghub.elsevier.com/retrieve/pii/S0167-0115(08)00218-8 DB - PRIME DP - Unbound Medicine ER -