Systemic quinpirole enhances tramadol analgesia in inflammatory pain, but not in neuropathic pain in male rats.

Autor: Mercado F; Laboratorio de Fisiología Celular, Dirección de Investigaciones en Neurociencias, Instituto Nacional de Psiquiatría Ramón de la Fuente Muñiz, Ciudad de México, Mexico., Segura-Chama P; Laboratorio de Fisiología Celular, Dirección de Investigaciones en Neurociencias, Instituto Nacional de Psiquiatría Ramón de la Fuente Muñiz, Ciudad de México, Mexico.; Investigador por México-CONAHCyT, Instituto Nacional de Psiquiatría Ramón de la Fuente Muñiz, Ciudad de México, Mexico., Mercado-Reyes JI; Laboratorio de Fisiología Celular, Dirección de Investigaciones en Neurociencias, Instituto Nacional de Psiquiatría Ramón de la Fuente Muñiz, Ciudad de México, Mexico., Mújica AA; Laboratorio de Fisiología Celular, Dirección de Investigaciones en Neurociencias, Instituto Nacional de Psiquiatría Ramón de la Fuente Muñiz, Ciudad de México, Mexico., Coffeen U; Laboratorio de Neurofisiología Integrativa, Dirección de Investigaciones en Neurociencias, Instituto Nacional de Psiquiatría Ramón de la Fuente Muñiz, Ciudad de México, Mexico., Pellicer F; Laboratorio de Neurofisiología Integrativa, Dirección de Investigaciones en Neurociencias, Instituto Nacional de Psiquiatría Ramón de la Fuente Muñiz, Ciudad de México, Mexico., Almanza A; Laboratorio de Fisiología Celular, Dirección de Investigaciones en Neurociencias, Instituto Nacional de Psiquiatría Ramón de la Fuente Muñiz, Ciudad de México, Mexico.
Jazyk: angličtina
Zdroj: The European journal of neuroscience [Eur J Neurosci] 2024 Dec; Vol. 60 (12), pp. 7195-7210. Date of Electronic Publication: 2024 Nov 27.
DOI: 10.1111/ejn.16617
Abstrakt: Pain is a morbidity or comorbidity with a high incidence that significantly impacts the well-being of patients. In this study, we evaluated the effects of systemic administration of tramadol, a weak mu-opioid receptor (MOR) agonist, plus quinpirole (a D2-like receptor agonist). The study was performed in naïve rats and in rats with induced inflammatory and neuropathic pain. To measure the antinociceptive effect of the drugs, thermonociceptive and mechanonociceptive stimuli were applied and the emotional aspects of pain were evaluated using conditional place preference (CPP) experiments. Systemic quinpirole produced an antinociceptive effect only in naïve male rats. In naïve female animals, a small but significant pronociceptive effect was observed following quinpirole application. Tramadol plus quinpirole in male animals reversed allodynia and hyperalgesia induced by inflammatory and neuropathic insults, which were not alleviated by either drug alone. CPP experiments revealed that systemic quinpirole plus tramadol treatment was effective only in an inflammatory pain model. To evaluate whether tolerance to the antinociceptive effect was prevented by the combination of the drugs, a repeated administration five-day trial of tramadol plus quinpirole was evaluated under inflammatory pain conditions; quinpirole only slightly prevented the antinociceptive tolerance of MOR agonists. D2-like agonists are effective adjuvants for treating painful conditions in combination with a low dose of MOR agonists. Our results could lead to an investigation of whether these dopaminergic drugs in combination with opioids might reduce the MOR agonist dose while obtaining a higher analgesic effect with fewer side effects in humans.
(© 2024 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.)
Databáze: MEDLINE
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