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国立情報学研究所で電子化したコンテンツを使用している。

The neuropeptides dynorphin and cholecystokinin (CCK), and their associated pronociceptive effects were investigated in the RVM. Utilizing a nerve-injury model (SNL), RT-PCR analysis revealed increases (p<0.05) of prodynorphin mRNA, and bradyinkin, B1- and B2-receptor mRNA, post-SNL, 14-days, 2-days, and 14-days, respectively. Administration of dynorphin into the RVM produced both acute and long-lasting (>30-days) tactile hypersensitivity. Administration of the B1-antagonist, DALBK and the B2-antagonist, Hoe-140, into the RVM significantly attenuated dynorphin-induced tactile hypersensitivity. Nerve-injury induced tactile hypersensitivity was significantly reversed by RVM administration of dynorphin antiserum or the B2-antagonist, Hoe-140. These data suggest that dynorphin is up-regulated in the RVM in nerve-injury, and via the activation of bradykinin receptors in the RVM, produces abnormal pain. Like dynorphin, CCK is up-regulated in the RVM in nerve-injury, with studies suggesting that elevated levels of CCK in the RVM mediate pronociceptive activity through CCK2 receptor activation, resulting in enhanced spinal nociceptive transmission. At present, it is unknown what key neurotransmitters are mediating this RVM CCK-driven effect at the level of the spinal cord. Here, spinal cerebrospinal fluid (CSF) levels of serotonin (5-HT) and prostaglandin E2 (PGE2) were measured in the lumbar spinal cord in naïve rats following CCK administration into the RVM. Following RVM CCK microinjection, an approximate 5-fold increase in spinal (CSF) PGE2 levels was observed, as compared to baseline controls. PGE2 levels showed a progressive increase with peak levels observed at the 80-minute post-CCK injection timepoint, whereas 5-HT levels in the spinal CSF remained unchanged following CCK administration into the RVM. This release of PGE2 coincided with the timecourse for CCK-induced mechanical hypersensitivity. Administration of the CCK2-antagonist YM022 prior to CCK into the RVM, significantly attenuated (>50%) the release of PGE2 in the spinal cord. The non-selective COX-inhibitor naproxen and the 5-HT3 antagonist ondansetron, both administered intrathecally, significantly attenuated RVM CCK-induced hindpaw tactile hypersensitivity. In summary, these data suggest a bradykinin- or CCK2-receptor antagonist could be used alone or in conjunction with current therapies in the treatment of chronic pain.

A Doença de Parkinson (DP) é a segunda doença neurodegenerativa mais comum na população, sendo seus mecanismos estudados em modelos animais. Há evidências de que alguns sistemas de comunicação celular podem modular o desenvolvimento da DP. Os canais de potencial transiente (TRPs) e receptores purinérgicos parecem envolvidos com a neurodegeneração e podem contribuir no desenvolvimento da DP, por outro lado, as cininas parecem estar relacionadas com a neuroproteção. O objetivo deste estudo foi avaliar a expressão e o envolvimento destes receptores de membrana no modelo da DP induzida por 6-OHDA em camundongos (C57Bl/6) injetados com agonista (BK) e antagonista (HOE-140) do receptor B2, e antagonista de TRPM7 (Carvacrol); e em nocautes do receptores B2, pelas técnicas de imuno-histoquímica e Western blotting. Os dados revelaram modulação destes receptores no modelo, e neuroproteção após o bloqueio do TRPM7. Assim, podemos sugerir que todos os receptores avaliados podem estar envolvidos na indução do modelo por 6-OHDA, sendo possíveis alvos terapêuticos para a DP. / Parkinson\'s disease (PD) is a second most common neurodegenerative disease in the population, and the mechanisms involved in these are studied in animal models. There is evidence that some systems can modulate the development of PD. Transient potential channels (TRPs) and purinergic receptors seem to be involved in neurodegeneration and may contribute to the development of PD; on the other hand, kininas appear to be related to neuroprotection. The aim of this study was to evaluate the expression and the involvement of these membrane receptors in the 6-OHDA-induced PD model in mice (C57Bl / 6) injected with agonist (BK) and antagonist (HOE-140) of B2 receptor; antagonist of TRPM7 (Carvacrol); and in B2 knockout knockouts, by immunohistochemistry and Western blotting techniques. The data revealed modulation of these receptors in the model, and neuroprotection after TRPM7 blockade. Thus, we can suggest that all the receptors evaluated may be involved in the induction of the 6-OHDA model, and can be possible therapeutic targets for PD.