• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 50
  • 25
  • 9
  • 9
  • 5
  • 2
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • Tagged with
  • 116
  • 62
  • 56
  • 25
  • 22
  • 14
  • 14
  • 12
  • 12
  • 12
  • 12
  • 11
  • 11
  • 10
  • 10
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
61

Papel dos receptores de dopamina do Núcleo Accumbens na hiperalgesia crônica de origem inflamatória / The role of Nucleus Accumbens dopamine receptors in inflammatory chronic hyperalgesia

Dias, Elayne Vieira, 1975- 23 August 2018 (has links)
Orientador: Carlos Amilcar Parada / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-23T21:05:03Z (GMT). No. of bitstreams: 1 Dias_ElayneVieira_D.pdf: 15528641 bytes, checksum: d53f9d8a514c6239af90a41cfe787afb (MD5) Previous issue date: 2013 / Resumo: O resumo poderá ser visualizado no texto completo da tese digital / Abstract: The complete abstract is available with the full electronic document / Doutorado / Fisiologia / Doutora em Biologia Funcional e Molecular
62

Mecanismos envolvidos na ação hiperalgésica induzida pela ativação de receptores P2X3 e P2X2/3 no músculo gastrocnêmio de ratos / Mechanisms underling the role of P2X3 and P2X2/3 receptors in mechanical hyperalgesia in gastrocnemius muscle of rats

Schiavuzzo, Jalile Garcia, 1980- 24 August 2018 (has links)
Orientador: Maria Cláudia Gonçalves de Oliveira Fusaro / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Ciências Aplicadas / Made available in DSpace on 2018-08-24T04:40:35Z (GMT). No. of bitstreams: 1 Schiavuzzo_JalileGarcia_M.pdf: 1205741 bytes, checksum: b599c1bee7cda79ed3554fcb789eea9d (MD5) Previous issue date: 2013 / Resumo: Existem evidências do envolvimento do ATP via ativação do receptor P2X3 na dor muscular. Portanto, o objetivo deste estudo foi verificar se a ativação do receptor P2X3 no músculo gastrocnêmio de ratos induz hiperalgesia mecânica, e em caso afirmativo, analisar os mecanismos inflamatórios pelo qual os receptores P2x3 induzem hiperalgesia mecânica. O Antagonista não seletivo para o receptor P2X3 ?,?meATP foi administrado no músculo gastrocnêmio de ratos, induzindo hiperalgesia, a qual foi significativamente reduzida pelo antagonista seletivo do receptor P2X3 e P2X2/3 - A-317491. A hiperalgesia mecânica induzida pelo ?,?meATP foi reduzida pelo inibidor de ciclooxigenase Indometacina, pelo antagonista seletivo do receptor de Bradicinina B1 e B2- Dalbk e Bradyzide, respectivamente, antagonista dos adrenoceptores ?1 e ?2 - Atenolol e ICI 118,551 respectivamente, e inibidor não específico de selectinas Fucoidan. O ?,?meATP também induziu o aumento da concentração local de citocinas pro inflamatórias TNF-?, IL-1?, IL-6 e CIN e migração de neutrófilos. Juntos estes achados sugerem que o ?,?meATP induz hiperalgesia mecânica no músculo gastrocnêmio via ativação de receptor periférico P2X3, o qual envolve bradicinina, prostaglandinas e aminas simpatomiméticas e migração de neutrófilos. Portanto, nós sugerimos que os receptores P2X3 sejam um importante alvo no controle da dor muscular / Abstract: There is evidence of the involvement of endogenous ATP via activation of P2X3 in muscle pain. Therefore, the aim of this study was to verify whether the activation of P2X3 receptors in the gastrocnêmio muscle of rats induces mechanical hyperalgesia and, if so, to analyze the inflammatory mechanisms by which P2X3 receptors induce mechanical hyperalgesia. Intramuscular administration of the non-selective P2X3 receptor agonist ?,?-meATP in the gastrocnemius muscle of rats induced mechanical hyperalgesia, which was significantly reduced by the selective P2X3 and P2X2/3 receptors antagonist A-317491. The ?,?-meATP-induced mechanical hyperalgesia was prevented by the indomethacin cyclooxygenase inhibitor, the selective bradykinin B1- or B2- receptor antagonist DALBK and bradyzide, respectively, the ?1- or ?2-adrenoceptor antagonist atenolol and ICI 118,551, respectively, and the nonspecific selectin inhibitor fucoidan. ?,?-meATP also induced increase in the local concentration of the pro-inflammatory cytokines TNF-?, IL-1?, IL-6 and CINC-1 and the neutrophil migration. Together, these findings suggest that ?,?-meATP induced mechanical VIII hyperalgesia in the gastrocnemius muscle of rats via activation of peripheral P2X3 receptors, which involves bradykinin, prostaglandins, sympathetic amines, pro-inflammatory cytokines and neutrophil migration. Therefore, we suggest that P2X3 receptors are important targets to control muscle inflammatory pain / Mestrado / Biodinâmica do Movimento Humano e Esporte / Mestra em Ciências da Nutrição e do Esporte e Metabolismo
63

Papel da Janus Quinase 2 expressa em tecido nervoso na hiperalgesia inflamatória / Role of neural tissue expressed Janus Kinase 2 in inflammatory hyperalgesia

Vieira, Andre Schwambach, 1982- 20 August 2018 (has links)
Orientador: Carlos Amilcar Parada / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-20T09:59:35Z (GMT). No. of bitstreams: 1 Vieira_AndreSchwambach_D.pdf: 871138 bytes, checksum: fc1ecaa5a27015a5ae9ed72d9687b540 (MD5) Previous issue date: 2012 / Resumo: A hiperalgesia inflamatória resulta da sensibilização de nociceptores aferentes periféricos induzida por mediadores inflamatórios. A prostaglandina E2 (PGE2) é uma das principais moléculas sinalizadoras envolvidas na hiperalgesia, sendo capaz de agir diretamente em nociceptores, induzindo mudanças nas propriedades de transdução sensorial destas células. A Janus Quinase 2 (JAK2) é uma molécula sinalizadora intracelular geralmente associada ao mecanismo de ação de citocinas, sendo que sua atividade pode ser induzida em nociceptores após uma inflamação periférica. Entretanto, não existem evidencias do envolvimento direto da JAK2 na sensibilização de nociceptores mediada pela PGE2. Assim o objetivo deste trabalho foi de explorar o possível papel da JAK2 na sensibilização mediada pela PGE2. Em neurônios do gânglio da raiz dorsal (DRG) em cultura foi observado que a PGE2 altera o influxo de cálcio induzido pela capsaicina, e a pré-incubação das células com o inibidor seletivo da JAK2, AG490, foi capaz de bloquear este efeito. Adicionalmente, a administração intratecal de AG490 em ratos reduziu a hiperalgesia induzida pela administração subcutânea e local de PGE2 ou carragenina. A administração intratecal de AG490 também bloqueou a ativação da PKCepsilon induzida no DRG L5 ispsilateral após inflamação na pata. Em conclusão o presente trabalho demonstra que a JAK2 expressa no DRG pode possuir um papel na sensibilização de nociceptores induzida por um evento inflamatório periférico. Desta forma a inibição da JAK2 pode ser um novo alvo farmacológico para o controle da hiperalgesia inflamatória / Abstract: Inflammatory hyperalgesia results from the sensitization of peripheral afferent nociceptors by inflammatory mediators. Prostaglandin E2 (PGE2) is one of the major signaling molecules involved in hyperalgesia, being able to act directly on nociceptors, inducing sensitization. The Janus Kinase 2 (JAK2) is an intracellular signaling molecule generally associated with cytokines signaling pathway, and its activity can be increased in nociceptors after peripheral inflammation. However, there are no evidences about the role JAK2 directly plays in PGE2-induced sensitization of nociceptors. Therefore, the aim of the present study was to explore a possible role for JAK2 in PGE2 mediated sensitization. The data of this study showed in cultured dorsal root ganglion (DRG) neurons, that the administration of PGE2 alters capsaicin-induced calcium transients, and the pre-incubation of the cells with the JAK2 selective inhibitor AG490 blocks this effect. In addition, the intrathecal administration of AG490 in rats reduces the hyperalgesia induced by local administration of PGE2 or carrageenan in the hindpaw. AG490 intrathecal administration also blocks PKCepsilon activation in the ipsilateral L5 DRG induced by inflammation of peripheral tissue. In conclusion, the present study indicates that the JAK2 expressed in the DRG may have a role in the sensitization of nociceptors by a peripheral inflammatory event. Moreover, the inhibition of JAK2 may be a possible novel pharmacological target for the control of the inflammatory hyperalgesia / Doutorado / Fisiologia / Doutor em Biologia Funcional e Molecular
64

Análise do efeito da laserterapia de baixa intensidade na nocicepção, expressão de mediadores inflamatórios, neutrófilos e macrófagos na fase aguda de artrite reumatóide experimental em ratos / Analysis of lasertherapy effects on nociception,inflammatory mediators expression, neutrophils and macrophages on acute phasys of experimental rheumatoid arthritis in rats

Alves, Ana Carolina Araruna 29 March 2016 (has links)
Submitted by Nadir Basilio (nadirsb@uninove.br) on 2018-06-21T15:40:31Z No. of bitstreams: 1 Ana Carolina Araruna Alves.pdf: 1155545 bytes, checksum: 5e9fda24285778105d5ac0d8276f9036 (MD5) / Made available in DSpace on 2018-06-21T15:40:31Z (GMT). No. of bitstreams: 1 Ana Carolina Araruna Alves.pdf: 1155545 bytes, checksum: 5e9fda24285778105d5ac0d8276f9036 (MD5) Previous issue date: 2016-03-29 / Rheumatoid Arthritis (RA) treatment in the last decades has evolved medications with cytokine inhibitors, which though they are today considered the gold standard in RA treatment, still do not guarantee complete remission from the disease or from hyperalgesia, and it is know that the Photobiostimulation (PBM) is also capable of acting on the expression of pro-inflammatory cytokines, being in this way an alternative treatment for RA. This research had as its objective the analysis and comparison of the effects of PBM in the acute phase of experimental RA in terms of nociception, of the number of inflammatory cells (neutrophils, macrophages, lymphocytes), and of the protein expression of inflammatory mediators (TNF-α, IL-6, IL-10), in the lavage and joint cartilage of rats. 49 male Wistar rats were used, with an approximate age of 90 days and a body weight varying from 250 to 300g. The animals were randomly distributed in 3 groups, with 21 animals in each experimental group (Rheumatoid arthritis group – RA) and the group treated with PBM (RA-LLLT), and with 7 animals in the control group. Each group was arrranged in three distinct experimental periods according to the time of euthanasia (6 hours, 24 hours, and 48 hours). For the reproduction of the lesion the animals were submitted to two inductions: the first consisted in a subcutaneous infiltration in the dorsal of each animal (in the RA and RA-LLLT groups) using 500 µg of mBSA diluted in a solution of 100 µL of complete Adjuvant de Freund (CFA), and 100 µL of PBS, with this procedure being repeated weekly for 21 days. On the 28th day, an intrajoint induction was carried out with 10 µg of mBSA diluted in 10µL of PBS, in the joint space of the right hind paw of each animal. After the joint induction, the treatment on the RA-LLLT group began, using a DMC® brand Photon Laser III, with a wave length of λ 808 nm, active medium of Gallium Arsenide, and Aluminium (AsGaAI), with a potency of 50 mW (potency density of 1,78 W/cm2) and area of the beam 0,028cm2. The final dose was of 2J, the density of energy of 71,2 J/cm2, and time of 40s by point. At the end of each test period (6 hours, 24 hours, and 48 hours) the animals were submitted to an evaluation of their nociception, followed by the extraction of joint lavage and joint cartilage, which were sent for analysis of the total count and differential cells, and for protein expression of the inflammatory mediators described. The results demonstrate biomodulation in the expression of neutrophils and macrophages amongst the control group and RA, as well as in the cytokines IL-6 and IL-10, contributing daily to the attenuation of hyperalgesia by the PBM. / O tratamento para Artrite Reumatoide (AR) com inibidores de citocinas tem sido considerado padrão-ouro nas últimas décadas embora ainda não garantam a remissão completa da doença ou da hiperalgesia, sabe-se que a Laserterapia de Baixa Intensidade (LBI) também é capaz de atuar na expressão das citocinas pró-inflamatórias, podendo ser assim, uma alternativa de tratamento para a AR. Este trabalho teve como objetivo analisar os efeitos da LBI na fase aguda de AR experimental sobre a nocicepção, sobre o número de células inflamatórias (neutrófilos, macrófagos, e linfócitos), e sobre a expressão proteica de mediadores inflamatórios (TNF-α, IL-6, IL-10) no lavado e cartilagem articular de ratos. Foram utilizados 49 ratos Wistar, machos, com idade aproximada de 90 dias e peso corporal variando de 250 a 300 g. Os animais foram distribuídos aleatoriamente em 3 grupos, com 21 animais em cada grupo experimental (grupo Artrite Reumatoide - RA e o grupo tratado com laser AR-LBI), e 7 animais no grupo controle. Cada grupo foi composto por 3 tempos experimentais distintos de acordo com o tempo da eutanásia (6 horas, 24 horas e 48 horas). Para a reprodução da lesão os animais foram submetidos a duas induções: a primeira consistiu em uma infiltração subcutânea no dorso de cada animal (nos grupos AR e AR-LBI) utilizando-se 500 µg de mBSA diluído em uma solução de 100 µL de Adjuvante completo de Freund (CFA), e 100µL de PBS, esse procedimento foi repetido semanalmente por 21 dias. No 28º dia, foi realizada uma indução intra-articular com 10 µg de mBSA diluído em 10µL PBS, no espaço articular da pata direita traseira de cada animal. Após a indução articular, deu-se início ao tratamento no grupo AR-LBI, por meio do laser da marca DMC® modelo Photon Laser III, com comprimento de onda de λ 808 nm, meio ativo de Arsenieto de Gálio e Alumínio (AsGaAI), com potência de 50 mW (densidade de potência de 1,78 W/cm2), área do feixe de 0,028cm2 e aplicação sob a forma de dois pontos pelo método transcutâneo nos compartimentos medial e lateral da articulação, dose final foi de 2J, densidade de energia de 71,2 J/cm2, e tempo 40s, por ponto. Ao final de cada período experimental (6 horas, 24 horas e 48 horas) os animais foram submetidos à avaliação da nocicepção, seguido de extração do lavado articular e da cartilagem articular, que foram encaminhados às análises de contagem total e diferencial de células, e da expressão proteica dos mediadores inflamatórios descritos. Os resultados demonstram biomodulação da LBI principalmente na expressão de neutrófilos e macrófagos entre os grupos controle e AR, bem como nas citocinas IL-6 e IL-10, contribuindo diretamente para a atenuação da hiperalgesia.
65

Modulation of Nociceptive Transmission by Pituitary Adenylate Cyclase Activating Polypeptide in the Spinal Cord of the Mouse

Ohsawa, Masahiro, Brailoiu, G. Cristina, Shiraki, Maho, Dun, Nae J., Paul, Kirstein, Tseng, Leon F. 01 November 2002 (has links)
Superficial layers of the dorsal horn receive a dense plexus of nerve fibers immunoreactive to pituitary adenylate cyclase activating polypeptide (PACAP). In vivo experiments were conducted in the mice to evaluate the effects of PACAP-38, herein referred to as PACAP, PACAP receptor antagonist PACAP(6-38) and PACAP-antiserum on nociceptive behaviors induced by radiant heat, intrathecally administered N-methyl-D-aspartate (NMDA) or intraplantarly administered formalin. PACAP (0.05-0.5μg) dose-dependently decreased the paw-withdrawal latencies induced by thermal stimulation and enhanced the aversive licking and biting behaviors induced by intrathecally injected NMDA. Pretreatment with the PACAP receptor antagonist PACAP(6-38) (0.5-2μg) or PACAP-antiserum (1:500-2000 dilution) dose-dependently attenuated the second phase, but not the first phase, of nociceptive responses to formalin. Next, the effects of PACAP on NMDA- and kainate-induced currents evoked in single dorsal horn neurons were studied. Whole-cell patch recordings were made from superficial dorsal horn neurons of spinal cord slices from 14- to 20-day-old mice. PACAP at the concentrations of 100 and 200nM, which caused no significant change of holding currents, increased NMDA-but not kainate-induced currents in superficial dorsal horn neurons. Our results suggest that exogenously applied PACAP sensitizes the dorsal horn neurons to formalin stimulation, and facilitates NMDA receptor-mediated nociceptive response. As a corollary, PACAP, which may be released from primary afferent fibers potentiates nociceptive transmission to the dorsal horn by interacting primarily with NMDA receptors.
66

Effect of Plantar Local Anesthetic Injection on Dorsal Horn Neuron Activity and Pain Behaviors Caused by Incision

Pogatzki, Esther M., Vandermeulen, Erik P., Brennan, Timothy J. 18 June 2002 (has links)
Hypersensitivity after tissue injury is an expression of neuronal plasticity in the central nervous system. This has been explored most extensively using in vitro preparations and animal models of inflammatory pain and chemical irritation. For pain after surgery, a similar process has been proposed. In the present study, we examined dorsal horn neuron (DHN) sensitization using the plantar incision model for post-operative pain. In behavioral experiments, the effect of a local anesthetic injection (or saline vehicle) 15min before plantar incision on pain behaviors several days after incision was studied. Bupivacaine injection before incision prevented pain behaviors until 4h afterwards; injection after incision produced the same effect. One day after incision, pain behaviors were not different between rats injected with saline or bupivacaine. In neurophysiologic experiments, however, bupivacaine injection blocked activation of DHNs during incision. One hour after incision, expansion of receptive fields (RFs) to pinch and increased background activity occurred in 14 of 16 neurons in the saline group but only in two of 22 neurons in the bupivacaine group. The difference was not due to a systemic effect of bupivacaine. Ten sensitized neurons were studied using the injection of bupivacaine 90min after incision. Increased background activity (n=7) and expanded RFs (n=7) were reversed by bupivacaine. Sensitization was re-established in seven of eight neurons 2h after injection as the local anesthetic dissipated. These results indicate that activation of DHNs during plantar incision and sensitization 1h later are not necessary for subsequent pain behaviors. Because sensitization was reversed 90min after plantar incision and then re-established as the local anesthetic effect diminished, enhanced responsiveness of DHN requires ongoing afferent input during the first day after incision.
67

Evaluating Sensory Abnormalities in Mice after Spinal Cord Injury and the Anatomical Evidence for Likely Mechanisms

Hoschouer, Emily Laurel 15 January 2010 (has links)
No description available.
68

Le récepteur métabotropique du glutamate 4 : une cible thérapeutique potentielle pour les douleurs chroniques? / The metabotropic glutamate receptor type 4 : a potential therapeutic target for chronic pain?

Vilar, Bruno 27 June 2012 (has links)
Les douleurs chroniques et notamment les douleurs neuropathiques sont particulièrement difficiles à traiter par les solutions thérapeutiques actuellement disponibles. Par conséquent, il existe un besoin crucial de découvrir et d'exploiter de nouveaux concepts d'antalgiques afin de traiter ce type de douleurs. Parmi les différentes pistes possibles, le système glutamatergique semble particulièrement intéressant puisque le glutamate est le principal neurotransmetteur propageant l'information douloureuse. Notre hypothèse est que l'activation du récepteur mGlu4 spinal inhiberait la neurotransmission glutamatergique et réduirait donc l'excès de douleur observé lors de douleurs chroniques. Grâce notamment au développement du premier agoniste orthostérique sélectif de mGlu4, nous avons mis en évidence que le récepteur mGlu4 n'altère pas la perception de la douleur aiguë mais qu'il influe, au contraire, sur l'aspect pathologique de la douleur en inhibant l'allodynie et l'hyperalgie mécanique ou thermique présentes lors de douleurs chroniques. Nous montrons que la modulation de l'hypersensibilité par mGlu4 semble provenir de sa capacité à inhiber la transmission glutamatergique via un couplage négatif avec les canaux calciques de type N au niveau de la couche II de la moelle épinière et plus particulièrement au niveau des fibres exprimant le transporteur vésiculaire VGLUT3. L'ensemble de nos résultats permettent de valider le récepteur mGlu4 spinal comme une cible thérapeutique potentielle pour le traitement des douleurs chroniques. En effet, les agonistes de mGlu4 pourraient être des antalgiques puissants et sélectifs des douleurs pathologiques. / Chronic pain and in particular neuropathic pain are particularly difficult to treat by therapeutic options currently available. Therefore, it is a crucial to develop new concepts of analgesics to treat this type of pain. Among the various possibilities, targeting the glutamatergic system seems to be particularly interesting since glutamate is the main neurotransmitter propagating the pain information. Our hypothesis is that the activation of spinal mGlu4 receptor would inhibit the spinal glutamatergic neurotransmission and would thus reduce the excess of pain observed in chronic pain.Thanks to the development of the first orthosteric agonist selective for mGlu4 and the use of transgenic animals, we demonstrated that mGlu4 receptor does not alter the perception of acute pain but that it does affect the pathological aspect of pain by inhibiting the allodynia and the hyperalgesia (mechanical and thermal) usually observed in chronic pain. We show that the mGlu4 modulation of the hypersensitivity seems to result from the ability of the receptor to inhibit the glutamatergic transmission through a negative coupling with N-type calcium channels in the lamina II of the spinal cord and especially at the level of fibers expressing the vesicular transporter VGLUT3. Taken together, our results validate spinal mGlu4 as a potential therapeutic target for the treatment of chronic pain. Indeed, mGlu4 agonists could be potent and selective painkillers of pathological pain.
69

Análise farmacológica comparativa da pancreatite experimental induzida por fosfolipase A2 secretória do veneno de serpente Crotalus durissus terrificus e fosfolipase A2 de mamífero em ratos: papel das fibras C e do sulfeto de hidrogênio. / Comparative pharmacological analysis of experimental pancreatitis induced secretory phospholipase A2 from snake venom Crotalus durissus terrificus and phospholipase A2 mammals in rats: role of the C fibers and hydrogen of sulphide.

Ramos, Cristiane Isabel Silva Mangialardo 02 May 2017 (has links)
A pancreatite aguda (PA), condição inflamatória do pâncreas caracterizada por dor abdominal e concentrações elevadas de enzimas pancreáticas e outras (ex.: amilase, fosfolipase A2, FLA2), representa a principal causa de hospitalização das doenças gastrointestinais. Entretanto, a patogênese da PA continua pouco compreendida e os tratamentos escassos. Nesse sentido, os objetivos deste estudo foram: i) avaliar comparativamente os efeitos inflamatórios e algogênicos das FLA2s secretória do veneno da serpente Crotalus durissus terrificus (Cdt) e de mamífero (bovino) e, ii) determinar mecanismos envolvidos (neurogênicos e dependentes do sulfeto de hidrogênio (H2S), um recentemente descrito mediador endógeno). A PA foi induzida pela injeção da FLA2 (300 mg/kg) crotálica ou bovina no ducto biliopancreático de ratos anestesiados e pré-tratados com salina, antagonistas dos receptores NK1/NK2 (SR140333/SR48968, e.v., - 15 min) Na2S (doador de H2S, i.p., - 30 min) ou propargilglicina (PGly, inibidor da enzima CSE envolvida na síntese endógena de H2S, i.p., - 30 min). Após 4 horas, a FLA2 crotálica ou bovina promoveu edema pancreático, infiltração de neutrófilos, amilasemia sérica e hiperalgesia abdominal. A FLA2 crotálica também aumentou a geração de H2S pancreática, as concentrações séricas de GT-γ e AST e promoveu leucopenia. O SR140333, mas não o SR48968, inibiu a hiperalgesia induzida por ambas as FLA2s, mas não afetou a PA ou índices enzimáticos. Tratamento com a PGly reduziu a PA induzida por ambas as FLA2, mas inibiu somente a hiperalgesia evocada pela FLA2 bovina. O doador espontâneo de H2S (Na2S) reduziu a PA e hiperalgesia induzidas pela PLA2 crotálica, mas não a amilasemia. Conclui-se que ambas as FLA2s representam ferramentas farmacológicas importantes na indução da PA, pois conseguem mimetizar sinais clássicos da PA em humanos. Em termos mecanisticos, conclui-se que enquanto a ativação do receptor NK1 consiste num mecanismo comum de regulação da resposta sensitiva abdominal (hiperalgésica) frente as duas FLA2s, o papel (protetor ou deletério) do H2S neste modelo ainda não está estabelecido. / Acute pancreatitis (AP), an inflammatory condition of the pancreas characterized by severe abdominal pain and increased levels of pancreatic enzymes and others in the blood (e.g. amilase, phospholipase A2, PLA2), is the leading cause of gastrointestinal hospitalization worldwide. Nevertheless, the pathogenesis of AP still not fully understood and treatments are scant. This study aimed: i) to evaluate comparatively the inflammatory and algesic effects of PLA2 obtained from the venom of Crotalus durissus terrificus (PLA2 Cdt) snake or mammalian (bovine) and, ii) to establish involved mechanisms focusing on neurogenic aspects and the recent gasomediator (hydrogen sulfide, H2S). AP was induced by the injection of bovine PLA2 or sPLA2 from Cdt venom (300 μg/kg) into the common bile duct of anaesthetized rats pretreated with the NK1 or Nk2 receptor antagonists (SR140333/SR48968, i.v., - 15 min), with the H2S donor (Na2S, i.p., - 30 min) or the inhibitor of CSE, an enzyme involved in the endogenous H2S synthesis (Propargylglycin, PGly i.p., - 30 min). After 4 hours, both mammalian and crotalic PLA2s caused pancreatic oedema, local neutrophil infiltration, serum hyperamylasemia and abdominal hyperalgesia. Increased pancreatic production of H2S, serum levels of γ-GT and AST and leukopenia were also observed in Cdt-induced AP. SR140333, but not SR48968, blocked the abdominal hyperalgesia induced by both PLAs but failed to significantly affect the inflammatory response and increased enzymes concentrations in this model. PGly attenuated both mammalian and crotalic PLA2s-induced AP, but inhibited only the abdominal hyperalgesia evoked by bovine PLA,sub>2. Spontaneous H2S donor (Na2S) reduced crotalic PLA2-induced AP and associated abdominal hyperalgesia but failed to affect hyperamylasemia. In conclusion, both mammalian and crotalic PLA2 act as an important pharmacological tool since they can mimic signs and symptoms of human AP. Whereas NK1 receptor (neurogenic mechanism) mediates abdominal hyperalgesia is likely to be the common mechanism involved in AP evoked by both PLA2s, this study still raising questions regarding the role (protective or deleterious) of H2S in the pathophysiology of AP and related pain process.
70

Caracterização das gelatinases no gânglio trigeminal durante o desenvolvimento de inflamação crônica temporomandibular em ratos / Characterization of gelatinases in the trigeminal ganglion during development of chronic temporomandibular inflammation in rats

Nascimento, Glauce Crivelaro do 03 May 2011 (has links)
A dor é um importante sintoma que sinaliza danos teciduais ou agentes potencialmente prejudiciais ao organismo, evocando respostas sensoriais e motoras de proteção. A dor orofacial apresenta alta prevalência na sociedade atual, sendo esta condição associada a tecidos duros e moles da cabeça, face, pescoço e a estruturas intraorais. Considerando as dores orofaciais de origem músculo-esquelética, destacam-se àquelas causadas pela Disfunção Temporomandibular (DTM). A DTM apresenta etiologia multifatorial, caracterizada por quadros crônicos envolvendo a região cervical, a musculatura mastigatória e a articulação temporomandibular (ATM). Desde que a inflamação das ATMs é considerada a principal causa da dor em pacientes portadores de DTM, a busca por novas opções terapêuticas para esta disfunção envolve estudos desta articulação, abrangendo aspectos fisiológicos, morfológicos e moleculares. Considerando o processo inflamatório e os aspectos moleculares envolvidos no desenvolvimento desta condição, é possível que as enzimas proteolíticas extracelulares, destacando-se as Metaloproteinases da Matriz (MMPs), as quais estão envolvidas na reabsorção de colágeno e de outras macromoléculas, tenham participação ativa neste processo. Em particular, estudos demonstraram que as MMPs estão envolvidas na modulação da dor neuropática, bem como estão presentes no líquido sinovial de portadores de inflamação da ATM. Sendo assim, o objetivo deste trabalho foi avaliar a influência da administração do Adjuvant de Freund (CFA) intraarticular, bilateralmente nas ATMs de ratos, na sensibilidade mecânica e nociceptiva, bem como avaliar a expressão das MMPs, em particular da MMP-2 e MMP-9, no gânglio trigeminal, nas diferentes fases de desenvolvimento da inflamação. Os resultados mostraram que a inflamação das ATMs promoveu alodinia mecânica e hiperalgesia orofacial. Em adição, a administração de doxiciclina (inibidor inespecífico das MMPs) reduziu as alterações na sensibilidade mecânica e nociceptiva. A quantificação das MMPs no gânglio trigeminal demonstrou que o início da inflamação promove aumento da MMP-9 (1 e 3 dias), enquanto que nas fases tardias do processo inflamatório acompanha-se o aumento da expressão da MMP-2 (3, 7 e 10 dias). / Pain is an important symptom that signals tissue damage or potentially harmful agents to the body and evokes sensory and motor protection. The orofacial pain is a type of symptoms that appears in high prevalence in modern society. This painful condition is associated with hard and soft tissues of the head, face, neck and intraoral structures. Considering the pain of musculoskeletal origin, we can highlight those caused by temporomandibular dysfunction (TMD). The TMD has a multifactorial etiology, characterized primarily by chronic conditions involving the neck, the chewing muscles and temporomandibular joint (TMJ). Inflammation of the TMJ is considered the main cause of pain in patients with TMD. Thus, the search for new therapeutic options for this disorder involves studies in the TMJ region encompassing physiological, morphological and molecular aspects. Considering the inflammatory process as the main cause of pain present in TMD, it is extremely important to understand the molecular aspects involved in developing this condition. In this context, extracellular proteolytic enzymes, highlighting the metaloproteniases matrix metalloproteinases (MMPs) play major role in the resorption of collagen and other macromolecules. The proteolytic activity of these MMPs is controlled by tissue inhibitors of metalloproteinases (TIMPs), which contribute to the maintenance of metabolic balance and structure of the extracellular matrix. Therefore, the objective of this study was to assess whether the type MMP gelatinases (MMP-2 and MMP-9) of the trigeminal ganglion participate in the development of mechanical allodynia and hyperalgesia in rats orofacial chronic inflammation bilateral TMJ. Our results demonstrated the presence of orofacial hyperalgesia, as well as mechanical allodynia in animals with temporomandibular inflammation induced by CFA and an increase in the expression and activity of gelatinases in the trigeminal ganglion of these animals. Still, there was a decrease in nociceptive orofacial hipersensitivity in animals that received a non-specific inhibitor for MMPs (doxycycline, 30mg/kg/day) for 10 days.

Page generated in 0.0637 seconds