Diverse effects of Brilliant Blue G administration in models of trigeminal activation in the rat
Autor: | Alexandra Büki, Nikolett Szabadi, Gábor Nagy-Grócz, Anna M. László, Veronika Vraukó, Lilla Tar, Zsuzsanna Bohár, László Vécsei, Árpád Párdutz, Annamária Fejes-Szabó |
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Jazyk: | angličtina |
Rok vydání: | 2015 |
Předmět: |
Male
Orofacial pain Purinergic P2X Receptor Antagonists Calcitonin Gene-Related Peptide Drug Evaluation Preclinical Substance P Stimulation Pharmacology Calcitonin gene-related peptide Nociceptive Pain Rats Sprague-Dawley chemistry.chemical_compound Trigeminal ganglion Facial Pain Formaldehyde Rosaniline Dyes Animals Medicine Receptor Biological Psychiatry business.industry Analgesics Non-Narcotic Immunohistochemistry Electric Stimulation Disease Models Animal Psychiatry and Mental health Nociception Trigeminal Ganglion Neurology chemistry Vibrissae Anesthesia Neuropathic pain Receptors Purinergic P2X7 Neurology (clinical) medicine.symptom business Proto-Oncogene Proteins c-fos |
Popis: | 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. |
Databáze: | OpenAIRE |
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