RESUMO
Since zwitterionic benzenesulfonamide Nav1.7 inhibitors suffer from poor membrane permeability, we sought to eliminate this characteristic by replacing the basic moiety with non-basic bicyclic acetals and monocyclic ethers. These efforts led to the discovery of the non-zwitterionic aryl sulfonamide 49 as a selective Nav1.7 inhibitor with improved membrane permeability. Despite its moderate cellular activity, 49 exhibited robust efficacy in mouse models of neuropathic and inflammatory pain and modulated translational electromyogram measures associated with activation of nociceptive neurons.
Assuntos
Descoberta de Drogas , Modelos Biológicos , Canal de Sódio Disparado por Voltagem NAV1.7/metabolismo , Neurônios/efeitos dos fármacos , Nociceptividade/efeitos dos fármacos , Sulfonamidas/farmacologia , Administração Oral , Animais , Dor Crônica/induzido quimicamente , Dor Crônica/tratamento farmacológico , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Adjuvante de Freund , Células HEK293 , Humanos , Inflamação/induzido quimicamente , Inflamação/tratamento farmacológico , Masculino , Camundongos , Estrutura Molecular , Neurônios/metabolismo , Relação Estrutura-Atividade , Sulfonamidas/administração & dosagem , Sulfonamidas/químicaRESUMO
Pain sensitivity is a recognized feature of fibromyalgia syndrome (FMS) but the contribution of spinal nociceptive circuitry to this phenomenon is unknown. Therefore, the objectives were to study the changes in spinal nociception i.e. nociceptive flexion reflex (NFR) in patients with FMS and to investigate correlation if any, between NFR threshold, pain duration and tender points in FMS. One hundred and three patients with FMS and 74 healthy volunteers participated in the study. To record NFR, sural nerve was stimulated in the retro malleolar region and the reflex response was recorded from the short head of biceps femoris muscle. NFR was elicited at significantly lower [21.0(18.0-25.0)V] thresholds in FMS group when compared to healthy subjects [30.0(24.75-35.0)V; pâ¯=â¯0.001] indicating hyperalgesic response to electrocutaneous stimulation in FMS patients. The latency and other parameters of NFR were comparable in both the groups. No significant correlation was found among NFR threshold and pain duration or tender points. On the basis of results of present study, it may be concluded that the functional deficit of the spinal nociceptive system can contribute to hyperalgesia in FMS. This is first study that correlates a marker of central hyper-excitability (NFR threshold) with clinical symptoms (pain duration and tender points) of FMS.