RESUMEN
This study investigated whether the spinal or systemic treatment with the lipid resolution mediators resolvin D1 (RvD1), aspirin-triggered resolvin D1 (AT-RvD1) and resolvin D2 (RvD2) might interfere with behavioral and neurochemical changes in the mouse fibromyalgia-like model induced by reserpine. Acute administration of AT-RvD1 and RvD2 produced a significant inhibition of mechanical allodynia and thermal sensitization in reserpine-treated mice, whereas RvD1 was devoid of effects. A similar antinociceptive effect was obtained by acutely treating animals with the reference drug pregabalin. Noteworthy, the repeated administration of AT-RvD1 and RvD2 also prevented the depressive-like behavior in reserpine-treated animals, according to assessment of immobility time, although the chronic administration of pregabalin failed to affect this parameter. The induction of fibromyalgia by reserpine triggered a marked decrease of dopamine and serotonin (5-HT) levels, as examined in total brain, spinal cord, cortex and thalamus. Reserpine also elicited a reduction of glutamate levels in total brain, and a significant increase in the spinal cord and thalamus. Chronic treatment with RvD2 prevented 5-HT reduction in total brain, and reversed the glutamate increases in total brain and spinal cord. Otherwise, AT-RvD1 led to a recovery of dopamine levels in cortex, and 5-HT in thalamus, whilst it diminished brain glutamate contents. Concerning pregabalin, this drug prevented dopamine reduction in total brain, and inhibited glutamate increase in brain and spinal cord of reserpine-treated animals. Our data provide novel evidence, showing the ability of D-series resolvins AT-RvD1, and mainly RvD2, in reducing painful and depressive symptoms allied to fibromyalgia in mice.
Asunto(s)
Analgésicos/farmacología , Antidepresivos/farmacología , Ácidos Docosahexaenoicos/farmacología , Fibromialgia/tratamiento farmacológico , Fibromialgia/fisiopatología , Animales , Encéfalo/efectos de los fármacos , Encéfalo/fisiopatología , Depresión/tratamiento farmacológico , Depresión/fisiopatología , Modelos Animales de Enfermedad , Dopamina/metabolismo , Ácido Glutámico/metabolismo , Calor , Hiperalgesia/tratamiento farmacológico , Hiperalgesia/fisiopatología , Masculino , Ratones , Dolor Nociceptivo/tratamiento farmacológico , Dolor Nociceptivo/fisiopatología , Pregabalina , Serotonina/metabolismo , Médula Espinal/efectos de los fármacos , Médula Espinal/fisiopatología , Tacto , Ácido gamma-Aminobutírico/análogos & derivados , Ácido gamma-Aminobutírico/farmacologíaRESUMEN
Phα1ß toxin is a peptide purified from the venom of the armed spider Phoneutria nigriventer, with markedly antinociceptive action in models of acute and persistent pain in rats. Similarly to ziconotide, its analgesic action is related to inhibition of high voltage activated calcium channels with more selectivity for N-type. In this study we evaluated the effect of Phα1ß when injected peripherally or intrathecally in a rat model of spontaneous pain induced by capsaicin. We also investigated the effect of Phα1ß on Ca²âº transients in cultured dorsal root ganglia (DRG) neurons and HEK293 cells expressing the TRPV1 receptor. Intraplantar or intrathecal administered Phα1ß reduced both nocifensive behavior and mechanical hypersensitivity induced by capsaicin similarly to that observed with SB366791, a specific TRPV1 antagonist. Peripheral nifedipine and mibefradil did also decrease nociceptive behavior induced by intraplantar capsaicin. In contrast, ω-conotoxin MVIIA (a selective N-type Ca²âº channel blocker) was effective only when administered intrathecally. Phα1ß, MVIIA and SB366791 inhibited, with similar potency, the capsaicin-induced Ca²âº transients in DRG neurons. The simultaneous administration of Phα1ß and SB366791 inhibited the capsaicin-induced Ca²âº transients that were additive suggesting that they act through different targets. Moreover, Phα1ß did not inhibit capsaicin-activated currents in patch-clamp recordings of HEK293 cells that expressed TRPV1 receptors. Our results show that Phα1ß may be effective as a therapeutic strategy for pain and this effect is not related to the inhibition of TRPV1 receptors.
Asunto(s)
Analgésicos no Narcóticos/uso terapéutico , Modelos Animales de Enfermedad , Ganglios Espinales/efectos de los fármacos , Moduladores del Transporte de Membrana/uso terapéutico , Neuralgia/tratamiento farmacológico , Neuronas/efectos de los fármacos , Venenos de Araña/uso terapéutico , Analgésicos no Narcóticos/farmacología , Animales , Conducta Animal/efectos de los fármacos , Señalización del Calcio/efectos de los fármacos , Capsaicina , Células Cultivadas , Ganglios Espinales/citología , Ganglios Espinales/metabolismo , Ganglios Espinales/patología , Células HEK293 , Humanos , Proteínas de Insectos/farmacología , Proteínas de Insectos/uso terapéutico , Masculino , Moduladores del Transporte de Membrana/farmacología , Proteínas del Tejido Nervioso/antagonistas & inhibidores , Proteínas del Tejido Nervioso/genética , Proteínas del Tejido Nervioso/metabolismo , Neuralgia/metabolismo , Neuralgia/patología , Neuronas/citología , Neuronas/metabolismo , Neuronas/patología , Péptidos/farmacología , Péptidos/uso terapéutico , Ratas , Ratas Wistar , Proteínas Recombinantes/química , Proteínas Recombinantes/metabolismo , Venenos de Araña/farmacología , Canales Catiónicos TRPV/antagonistas & inhibidores , Canales Catiónicos TRPV/genética , Canales Catiónicos TRPV/metabolismoRESUMEN
The effects of trans-resveratrol (1) were evaluated in acute nociception models induced by capsaicin or glutamate in mice, in an attempt to further characterize its mechanism of action. The oral administration of 1 (50 and 100 mg/kg) reduced significantly the licking behavior elicited by capsaicin (1.6 µg/paw) or glutamate (10 µmol/paw). The co-administration of 1 into the mouse paw (200 µg/site) markedly prevented glutamate-induced licking, without affecting capsaicin responses. In addition, the intrathecal (it) injection of 1 (150 to 600 µg/site) greatly reduced the licking behavior caused by capsaicin, but not glutamate. Similarly, the intracerebroventricular injection of 1 (300 µg/site) caused a potent inhibition of capsaicin-induced nociception, while the glutamate responses remained unaffected. However, the co-administration of 1 (300 µg/site) reduced the biting behavior induced by spinal injection of glutamate (30 µg/site, it), leaving capsaicin (6.4 µg/site)-induced biting unaltered. Notably, the oral administration of 1 (100 mg/kg) inhibited significantly the capsaicin-induced increase of c-Fos and COX-2 labeling in the spinal cord and COX-2 expression in the cortex, but failed to affect c-Fos and COX-2 expression in the glutamate model. This study has explored the effects of 1 in both the capsaicin and glutamate models, extending current knowledge on the analgesic effects of trans-resveratrol.
Asunto(s)
Analgésicos/farmacología , Estilbenos/farmacología , Analgésicos/administración & dosificación , Animales , Conducta Animal/efectos de los fármacos , Capsaicina/administración & dosificación , Capsaicina/farmacología , Ciclooxigenasa 2/análisis , Ciclooxigenasa 2/genética , Modelos Animales de Enfermedad , Relación Dosis-Respuesta a Droga , Ácido Glutámico/administración & dosificación , Ácido Glutámico/farmacología , Masculino , Ratones , Estructura Molecular , Nocicepción/efectos de los fármacos , Dimensión del Dolor/efectos de los fármacos , Proteínas Proto-Oncogénicas c-fos/análisis , Proteínas Proto-Oncogénicas c-fos/genética , Resveratrol , Estereoisomerismo , Estilbenos/químicaRESUMEN
In spinal cord synaptosomes, the spider toxin PhTx3-4 inhibited capsaicin-stimulated release of glutamate in both calcium-dependent and -independent manners. In contrast, the conus toxins, ω-conotoxin MVIIA and xconotoxin MVIIC, only inhibited calcium-dependent glutamate release. PhTx3-4, but not ω-conotoxin MVIIA or xconotoxin MVIIC, is able to inhibit the uptake of glutamate by synaptosomes, and this inhibition in turn leads to a decrease in the Ca(2+)-independent release of glutamate. No other polypeptide toxin so far described has this effect. PhTx3-4 and ω-conotoxins MVIIC and MVIIA are blockers of voltage-dependent calcium channels, and they significantly inhibited the capsaicin-induced rise of intracellular calcium [Ca(2+)](i) in spinal cord synaptosomes, which likely reflects calcium entry through voltage-gated calcium channels. The inhibition of the calcium-independent glutamate release by PhTx3-4 suggests a potential use of the toxin to block abnormal glutamate release in pathological conditions such as pain.
Asunto(s)
Calcio/metabolismo , Capsaicina/farmacología , Ácido Glutámico/metabolismo , Neuropéptidos/toxicidad , Médula Espinal/metabolismo , Sinaptosomas/metabolismo , omega-Conotoxinas/toxicidad , Animales , Fluorescencia , Masculino , Ratas , Ratas Wistar , Venenos de Araña/toxicidad , Médula Espinal/efectos de los fármacos , Sinaptosomas/efectos de los fármacosRESUMEN
Calcium influx through neuronal voltage-sensitive calcium channels (VSCC S) mediates nociceptive information in the spinal dorsal horn. In fact, spinally administered VSCC S blockers, such as omega-conotoxin MVIIA, have analgesic effect apart of their low therapeutic index and many side effects. Here we study the analgesic potential of Ph alpha 1beta, a calcium channel blocker, in rodent models of acute and persistent pain. Spinally administered Ph alpha 1beta showed higher efficacy and long-lasting analgesia in a thermal model of pain, when compared with omega-conotoxin MVIIA. Moreover, Ph alpha 1beta was more effective and potent than omega-conotoxin MVIIA not only to prevent, but especially to reverse, previously installed persistent chemical and neuropathic pain. Furthermore, the analgesic action of both toxins are related with the inhibition of Ca2+-evoked release of pro-nociceptive neurotransmitter, glutamate, from rat spinal cord synaptosomes and decrease of glutamate overflow in cerebrospinal fluid. When side effects were assessed, we found that Ph alpha 1beta had a therapeutic index wider than omega- conotoxin MVIIA. Finally, recombinant Ph alpha 1beta expressed in Escherichia coli showed marked analgesic activity similar to the native toxin. Taken together, the present study demonstrates that native and recombinant Ph alpha 1beta have analgesic effects in rodent models of pain, suggesting that this toxin may have potential to be used as a drug in the control of persistent pathological pain.
Asunto(s)
Bloqueadores de los Canales de Calcio/administración & dosificación , Bloqueadores de los Canales de Calcio/aislamiento & purificación , Escherichia coli/metabolismo , Hiperalgesia/prevención & control , Hiperalgesia/fisiopatología , Dimensión del Dolor/efectos de los fármacos , Venenos de Araña/química , Analgésicos/administración & dosificación , Animales , Escherichia coli/genética , Hiperalgesia/diagnóstico , Masculino , Ratones , Proteínas Recombinantes/metabolismo , Venenos de Araña/genéticaRESUMEN
The purpose of the present work was to investigate the pharmacological action of a calcium channel-blocking toxin from the venom of the spider Phonetic nigriventer, Tx3-4 on calcium channels coupled to exocytosis of synaptic vesicles. Tx3-4 blocked KCl-induced exocytosis of synaptic vesicles with an IC50 of 1.1 nM. To investigate whether the target of Tx3-4 overlaps with known calcium channels that mediate calcium entry and exocytosis, we used omega-toxins that interact selectively with neuronal calcium channels. The results indicate that the main population of voltage-sensitive calcium channels altered by Tx3-4 is P/Q calcium channels. In conclusion, Tx3-4 is a potent inhibitor of calcium channels involved in the KCl-induced exocytosis of synaptic vesicles in brain cortical synaptosomes.
Asunto(s)
Canales de Calcio/efectos de los fármacos , Exocitosis/efectos de los fármacos , Neurotoxinas/farmacología , Venenos de Araña/farmacología , Animales , Encéfalo/ultraestructura , Bloqueadores de los Canales de Calcio/farmacología , Relación Dosis-Respuesta a Droga , Masculino , Neuropéptidos/farmacología , Cloruro de Potasio/farmacología , Ratas , Ratas Wistar , Sinaptosomas/efectos de los fármacosRESUMEN
In this work, we reported the synthesis and evaluation of the analgesic and anti-inflammatory properties of novel 3- or 4-substituted 5-trifluoromethyl-5-hydroxy-4,5-dihydro-1H-1-carboxyamidepyrazoles (where 3-/4-substituent=H/H, Me/H, Et/H, Pr/H, i-Pr/H, Bu/H, t-Bu/H, Ph/H, 4-Br-Ph/H and H/Me) designed in the exploration of the bioisosteric replacement of benzene present in salicylamide with a 5-trifluoromethyl-4,5-dihydro-1H-pyrazole scaffold. Target compounds were synthesized from the cyclocondensation of 4-alkoxy-1,1,1-trifluoromethyl-3-alken-2-ones with semicarbazide hydrochloride through a rapid one-pot reaction via microwave irradiation. In addition to spectroscopic data, the structure of the compounds was supported by X-ray diffraction. Subcutaneous administration of the 5-trifluoromethyl-4,5-dihydro-1H-pyrazoles decreased pain-related behavior during neurogenic and inflammatory phases of the formalin test in mice. Moreover, the more active analgesic compounds (3-/4-=Et/H and H/Me) significantly decreased carrageenan-induced paw edema in mice. The data obtained in this work suggest that the synthesized compounds could be promising candidates for the future development of novel analgesic and anti-inflammatory agents.