Noradrenergic-nitrergic interactions in the rat anococcygeus muscle: evidence for postjunctional modulation by nitric oxide.

Hdl Handle:
http://hdl.handle.net/10142/92763
Title:
Noradrenergic-nitrergic interactions in the rat anococcygeus muscle: evidence for postjunctional modulation by nitric oxide.
Authors:
Kasakov, L.; Belai, A.; Vlaskovska, M.; Burnstock, G.
Abstract:
1. The distribution of NADPH-diaphorase positive and catecholamine-containing nerve structures, and functional noradrenergic-nitrergic interactions, were studied in the rat anococcygeus muscle. 2. The morphological findings demonstrated NADPH-diaphorase positive neurons mostly as aggregates in intramural ganglia, nerve tracts and few single nerve fibres forming plexus-like structures. 3. The nitric oxide synthase inhibitor NG-nitro-L-arginine (L-NOARG) inhibited concentration-dependently the nitrergic relaxation, an effect reversed by L-arginine. The drug had dual effects on noradrenergic contractile responses: at lower concentrations (0.1-10 microM) it decreased the amplitude of contractions and this was not affected by L-arginine; higher concentrations (50-500 microM) potentiated the contractions, an effect that was prevented by L-arginine. 4. The electron acceptor, nitro blue tetrazolium (NBT) produced a rapid inhibition of the noradrenergic contractile responses (EC50 0.178 +/- 0.041 microM). The drug decreased the tone of the preparations. However, it potentiated concentration-dependently the nitrergic relaxations. 5. NBT (1 microM) had no significant effect on the relaxations induced by exogenously applied nitric oxide (NO)-donor sodium nitroprusside (SNP, 0.01-50 microM). However, the effect of NBT (0.1-10 microM) on the electrically induced relaxation was significantly decreased by L-NOARG (10 and 50 microM). The inhibition was of a non-competitive type. 6. Neither L-NOARG (100 microM) nor NBT (1 microM) had any effect on the spontaneous or electrically-induced release of 3H-radioactivity from the tissues preincubated in [3H]-noradrenaline. 7. It is concluded that L-arginine-NO pathway can modulate noradrenergic transmission in the rat anococcygeus muscle at postjunctional, but not prejunctional site(s).
Citation:
Noradrenergic-nitrergic interactions in the rat anococcygeus muscle: evidence for postjunctional modulation by nitric oxide. 1994, 112 (2):403-10 Br. J. Pharmacol.
Journal:
British journal of pharmacology
Issue Date:
Jun-1994
URI:
http://hdl.handle.net/10142/92763
PubMed ID:
8075857
Language:
en
ISSN:
0007-1188
Appears in Collections:
Department of Life Sciences Collection

Full metadata record

DC FieldValue Language
dc.contributor.authorKasakov, L.en
dc.contributor.authorBelai, A.en
dc.contributor.authorVlaskovska, M.en
dc.contributor.authorBurnstock, G.en
dc.date.accessioned2010-02-23T13:25:12Z-
dc.date.available2010-02-23T13:25:12Z-
dc.date.issued1994-06-
dc.identifier.citationNoradrenergic-nitrergic interactions in the rat anococcygeus muscle: evidence for postjunctional modulation by nitric oxide. 1994, 112 (2):403-10 Br. J. Pharmacol.en
dc.identifier.issn0007-1188-
dc.identifier.pmid8075857-
dc.identifier.urihttp://hdl.handle.net/10142/92763-
dc.description.abstract1. The distribution of NADPH-diaphorase positive and catecholamine-containing nerve structures, and functional noradrenergic-nitrergic interactions, were studied in the rat anococcygeus muscle. 2. The morphological findings demonstrated NADPH-diaphorase positive neurons mostly as aggregates in intramural ganglia, nerve tracts and few single nerve fibres forming plexus-like structures. 3. The nitric oxide synthase inhibitor NG-nitro-L-arginine (L-NOARG) inhibited concentration-dependently the nitrergic relaxation, an effect reversed by L-arginine. The drug had dual effects on noradrenergic contractile responses: at lower concentrations (0.1-10 microM) it decreased the amplitude of contractions and this was not affected by L-arginine; higher concentrations (50-500 microM) potentiated the contractions, an effect that was prevented by L-arginine. 4. The electron acceptor, nitro blue tetrazolium (NBT) produced a rapid inhibition of the noradrenergic contractile responses (EC50 0.178 +/- 0.041 microM). The drug decreased the tone of the preparations. However, it potentiated concentration-dependently the nitrergic relaxations. 5. NBT (1 microM) had no significant effect on the relaxations induced by exogenously applied nitric oxide (NO)-donor sodium nitroprusside (SNP, 0.01-50 microM). However, the effect of NBT (0.1-10 microM) on the electrically induced relaxation was significantly decreased by L-NOARG (10 and 50 microM). The inhibition was of a non-competitive type. 6. Neither L-NOARG (100 microM) nor NBT (1 microM) had any effect on the spontaneous or electrically-induced release of 3H-radioactivity from the tissues preincubated in [3H]-noradrenaline. 7. It is concluded that L-arginine-NO pathway can modulate noradrenergic transmission in the rat anococcygeus muscle at postjunctional, but not prejunctional site(s).en
dc.description.provenanceSubmitted by Abi Belai (a.belai@roehampton.ac.uk) on 2010-02-23T13:24:27Z No. of bitstreams: 0en
dc.description.provenanceApproved for entry into archive by Emily Selvidge(e.selvidge@roehampton.ac.uk) on 2010-02-23T13:25:12Z (GMT) No. of bitstreams: 0en
dc.description.provenanceMade available in DSpace on 2010-02-23T13:25:12Z (GMT). No. of bitstreams: 0 Previous issue date: 1994-06en
dc.language.isoenen
dc.subject.meshAnimals-
dc.subject.meshArginine-
dc.subject.meshElectric Stimulation-
dc.subject.meshHistocytochemistry-
dc.subject.meshMale-
dc.subject.meshMuscle Contraction-
dc.subject.meshMuscle Relaxation-
dc.subject.meshMuscles-
dc.subject.meshNADPH Dehydrogenase-
dc.subject.meshNeuromuscular Junction-
dc.subject.meshNitric Oxide-
dc.subject.meshNitroarginine-
dc.subject.meshNitroblue Tetrazolium-
dc.subject.meshNitroprusside-
dc.subject.meshNorepinephrine-
dc.subject.meshRats-
dc.subject.meshRats, Sprague-Dawley-
dc.titleNoradrenergic-nitrergic interactions in the rat anococcygeus muscle: evidence for postjunctional modulation by nitric oxide.en
dc.identifier.journalBritish journal of pharmacologyen
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