title: Diverse effects of Brilliant Blue G administration in models of trigeminal activation in the rat.
abstract: Activation of the trigeminal system plays an important role in the pathomechanism of headaches. A better understanding of trigeminal pain processing is expected to provide information helping to unravel the background of these diseases. ATP, a key modulator of nociceptive processing, acts on ligand-gated P2X receptors. Antagonists of the P2X7 receptors, such as Brilliant Blue G (BBG), have proved effective in several models of pain. We have investigated the effects of BBG after electrical stimulation of the trigeminal ganglion and in the orofacial formalin test in the rat. The right trigeminal ganglion of male rats was stimulated either with 5 Hz, 0.5 mA pulses for 5 min (mild procedure) or with 10 Hz, 0.5 mA pulses for 30 min (robust procedure), preceded by 50 mg/kg i.v. BBG. The animals were processed for c-Fos and calcitonin gene-related peptide (CGRP) immunohistochemistry. In the orofacial formalin test, 50 μL of 1.5 % formalin was injected into the right whisker pad of awake rats, following the pre-treatment with BBG. Behaviour was monitored for 45 min, and c-Fos and CGRP immunohistochemistry was performed. BBG attenuated the increase in c-Fos-positive cells in the caudal trigeminal nucleus (TNC) after robust stimulation, but not after mild stimulation. No alterations in CGRP levels were found with either methodology. BBG did not mitigate either the behaviour or the increase in c-Fos-positive cells in the TNC during the orofacial formalin test. These results indicate that P2X7 receptors may have a role in the modulation of nociception in the trigeminal system.
authors: MTA-SZTE Neuroscience Research Group, Semmelweis u. 6., Szeged, 6725, Hungary.
authors: Zsuzsanna
authors: Z
authors: Bohár
authors: Department of Neurology, Faculty of Medicine, Albert Szent-Györgyi Clinical Center, University of Szeged, Semmelweis u. 6., Szeged, 6725, Hungary.
authors: Gábor
authors: G
authors: Nagy-Grócz
authors: Department of Neurology, Faculty of Medicine, Albert Szent-Györgyi Clinical Center, University of Szeged, Semmelweis u. 6., Szeged, 6725, Hungary.
authors: Annamária
authors: A
authors: Fejes-Szabó
authors: Department of Neurology, University of Ulm, Oberer Eselsberg 45, 89081, Ulm, Germany.
authors: Lilla
authors: L
authors: Tar
authors: Department of Medical Physics and Informatics, Faculty of Medicine, Faculty of Science and Informatics, University of Szeged, Korányi fasor 9, Szeged, 6720, Hungary.
authors: Anna M
authors: AM
authors: László
authors: Department of Physiology, Faculty of Medicine, University of Szeged, Dóm tér 10, Szeged, 6720, Hungary.
authors: Alexandra
authors: A
authors: Büki
authors: Department of Neurology, Faculty of Medicine, Albert Szent-Györgyi Clinical Center, University of Szeged, Semmelweis u. 6., Szeged, 6725, Hungary.
authors: Nikolett
authors: N
authors: Szabadi
authors: Department of Neurology, Faculty of Medicine, Albert Szent-Györgyi Clinical Center, University of Szeged, Semmelweis u. 6., Szeged, 6725, Hungary.
authors: Veronika
authors: V
authors: Vraukó
authors: MTA-SZTE Neuroscience Research Group, Semmelweis u. 6., Szeged, 6725, Hungary. vecsei.laszlo@med.u-szeged.hu.|Department of Neurology, Faculty of Medicine, Albert Szent-Györgyi Clinical Center, University of Szeged, Semmelweis u. 6., Szeged, 6725, Hungary. vecsei.laszlo@med.u-szeged.hu.
authors: László
authors: L
authors: Vécsei
authors: Department of Neurology, Faculty of Medicine, Albert Szent-Györgyi Clinical Center, University of Szeged, Semmelweis u. 6., Szeged, 6725, Hungary.
authors: Árpád
authors: Á
authors: Párdutz
mesh_terms: D018712:Analgesics, Non-Narcotic / Q000494:pharmacology*; D000818:Animals; D015740:Calcitonin Gene-Related Peptide / Q000378:metabolism; D004195:Disease Models, Animal; D004353:Drug Evaluation, Preclinical; D004558:Electric Stimulation; D005157:Facial Pain / Q000188:drug therapy* / Q000473:pathology / Q000503:physiopathology; D005557:Formaldehyde; D007150:Immunohistochemistry; D008297:Male; D059226:Nociceptive Pain / Q000188:drug therapy* / Q000473:pathology / Q000503:physiopathology; D016760:Proto-Oncogene Proteins c-fos / Q000378:metabolism; D058920:Purinergic P2X Receptor Antagonists / Q000494:pharmacology*; D017207:Rats, Sprague-Dawley; D058486:Receptors, Purinergic P2X7 / Q000378:metabolism; D012394:Rosaniline Dyes / Q000494:pharmacology*; D012668:Trigeminal Ganglion / Q000187:drug effects* / Q000473:pathology / Q000503:physiopathology; D014738:Vibrissae
chemical_list: D018712:Analgesics, Non-Narcotic; D016760:Proto-Oncogene Proteins c-fos; D058920:Purinergic P2X Receptor Antagonists; D058486:Receptors, Purinergic P2X7; D012394:Rosaniline Dyes; D005557:Formaldehyde; D015740:Calcitonin Gene-Related Peptide; C004692:coomassie Brilliant Blue
keywords: Formalin test; P2X7 receptor; Trigeminal ganglion stimulation; Trigeminal system