RESUMO
In this study we surveyed a rat skeletal muscle RNA-Seq for genes that are induced by hindlimb immobilization and, in turn, become attenuated by leucine supplementation. This approach, in search of leucine-atrophy protection mediating genes, identified histone deacetylase 4 (HDAC4) as highly responsive to both hindlimb immobilization and leucine supplementation. We then examined the impact of leucine on HDAC4 expression, tissue localization, and target genes. A total of 76 male Wistar rats (~280 g) were submitted to hindlimb immobilization and/or leucine supplementation for 3, 7 and 12 days. These animals were euthanized, and soleus muscle was removed for further analysis. RNA-Seq analysis of hindlimb immobilized rats indicated a sharp induction (log2 = 3.4) of HDAC4 expression which was attenuated by leucine supplementation (~50%). Real-time PCR and protein expression analysis by Western blot confirmed increased HDAC4 mRNA after 7 days of hindlimb immobilization and mitigation of induction by leucine supplementation. Regarding the HDAC4 localization, the proportion of positive nuclei was higher in the immobilized group and decreased after leucine supplementation. Also, we found a marked decrease of myogenin and MAFbx-atrogin-1 mRNA levels upon leucine supplementation, while CAMKII and DACH2 mRNA levels were increased by leucine supplementation. Our data suggest that HDAC4 inhibition might be involved in the anti-atrophic effects of leucine.
Assuntos
Suplementos Nutricionais , Membro Posterior/patologia , Histona Desacetilases/metabolismo , Leucina/uso terapêutico , Músculo Esquelético/metabolismo , Animais , Peso Corporal , Membro Posterior/metabolismo , Elevação dos Membros Posteriores , Masculino , Microscopia de Fluorescência , Atrofia Muscular/patologia , RNA-Seq , Ratos , Ratos Wistar , Reação em Cadeia da Polimerase em Tempo Real , Transdução de SinaisRESUMO
NEW FINDINGS: What is the central question of this study? Ischaemia-reperfusion of peripheral tissues protects the heart from subsequent myocardial ischaemia-reperfusion injury, a phenomenon referred to as remote ischaemic preconditioning (rIPC). This study evaluated the possible myocardial triggers of rIPC. What is the main finding and its importance? Remote ischaemic preconditioning reduces infarct size through a vagal pathway and a mechanism involving phosphorylation of Akt and endothelial nitric oxide synthase, opening of mitochondrial ATP-dependent K(+) channels and an increase in mitochondrial H2 O2 production. All these phenomena occur before the myocardial ischaemia; hence, they could act as 'triggers' of rIPC. It has been proposed that remote ischaemic preconditioning (rIPC) activates a parasympathetic neural pathway. However, the myocardial intracellular mechanism of rIPC remains unclear. Here, we characterized some of the intracellular signals participating as rIPC triggers. Isolated rat hearts were subjected to 30 min of global ischaemia and 120 min of reperfusion (Non-rIPC group). In a second group, before the isolation of the heart, an rIPC protocol (three cycles of hindlimb ischaemia-reperfusion) was performed. The infarct size was measured with tetrazolium staining. Expression/phosphorylation of Akt and endothelial nitric oxide synthase (eNOS) and mitochondrial H2 O2 production were evaluated at the end of the rIPC protocol, before myocardial ischaemia-reperfusion. The rIPC significantly decreased the infarct size and induced Akt and eNOS phosphorylation. The protective effect on infarct size was abolished by cervical vagal section, l-NAME (an NO synthesis inhibitor) and 5-hydroxydecanoate (a mitochondrial ATP-dependent K(+) channel blocker). Mitochondrial production of H2 O2 was increased by rIPC, whereas it was abolished by cervical vagal section, l-NAME and 5-hydroxydecanoate. We conclude that rIPC activates a parasympathetic vagal pathway and a mechanism involving the phosphorylation of Akt and eNOS, the opening of mitochondrial ATP-dependent K(+) channels and the release of H2 O2 by the mitochondria. All these phenomena occur before myocardial ischaemia and could act as triggers of rIPC.
Assuntos
Infarto do Miocárdio/metabolismo , Isquemia Miocárdica/metabolismo , Traumatismo por Reperfusão Miocárdica/metabolismo , Miocárdio/metabolismo , Trifosfato de Adenosina/metabolismo , Animais , Ácidos Decanoicos/farmacologia , Coração/efeitos dos fármacos , Coração/fisiopatologia , Membro Posterior/efeitos dos fármacos , Membro Posterior/metabolismo , Peróxido de Hidrogênio/metabolismo , Hidroxiácidos/farmacologia , Precondicionamento Isquêmico Miocárdico/métodos , Masculino , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Reperfusão Miocárdica/métodos , NG-Nitroarginina Metil Éster/farmacologia , Óxido Nítrico Sintase Tipo III/metabolismo , Sistema Nervoso Parassimpático/efeitos dos fármacos , Sistema Nervoso Parassimpático/metabolismo , Fosforilação/efeitos dos fármacos , Fosforilação/fisiologia , Canais de Potássio/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Ratos , Ratos Wistar , Nervo Vago/efeitos dos fármacos , Nervo Vago/metabolismoRESUMO
We measured the effect of Schwann cell transplantation and complement factor 5a (C5a) receptor antagonist on nerve function recovery in rats with spinal cord injury. Experimental spinal cord injury was induced in eighty Wistar rats and these were randomly divided into four treatment groups: culture medium and saline injection (control group), Schwann cell injection (cell transplantation group), C5a receptor antagonist injection (C5a receptor antagonist group), and both Schwann cell and C5a receptor antagonist injections (combination group). Rear limb functional recovery was assessed 1, 2, 4, 6, and 8 weeks after the spinal cord injury with the tilt table test and the Basso, Beattie, Bresnahan scale. Sex-determining region Y (SRY) gene expression was measured at week 4 and horseradish peroxidase (HRP) labeling was used at week 8 to further assess the recovery of neuroelectrophysiological functions. The rear limb functional assessment showed that the combination group had better outcomes than the cell transplantation and C5a receptor antagonist groups. All treatment groups had better outcomes than control. Only the cell transplantation and combination groups showed SRY expression. The number of HRP-positive nerve fibers in the different groups ranked as follows: combination group > cell transplantation and C5a receptor antagonist > control. The refractory period and amplitude of the induced potential in the combination group were significantly greater than in the other three groups. These results suggest that the combination of Schwann cell transplantation and the C5a receptor antagonist enhances the regeneration of injured synapses and improves limb function and electrophysiology.
Assuntos
Membro Posterior/fisiologia , Regeneração Nervosa/fisiologia , Receptor da Anafilatoxina C5a/antagonistas & inibidores , Recuperação de Função Fisiológica/fisiologia , Células de Schwann/transplante , Traumatismos da Medula Espinal/fisiopatologia , Animais , Transplante de Células/métodos , Feminino , Membro Posterior/metabolismo , Masculino , Ratos , Ratos Wistar , Traumatismos da Medula Espinal/metabolismoRESUMO
The increase in PGE2 production by microsomal PGE synthase-1 (mPGES-1) in CNS contributes to the severity of the inflammatory and pain responses in the model of edema formation and hyperalgesia induced by carrageenan. PGI2, alike to PGE2, plays an important role in the inflammation. Low-level laser therapy (LLLT) has been used in the treatment of inflammatory pathologies, reducing both pain and the acute inflammatory process. In this work, we studied the effect of LLLT on the expression of both mPGES-1 and IP messenger RNA (mRNA), in either subplantar or total brain tissues obtained from rats submitted to model of edema formation and hyperalgesia induced by carrageenan administration. The test sample consisted of 30 rats divided into five groups: A1 (control-saline), A2 (carrageenan-0.5 mg/paw), A3 (carrageenan-0.5 mg/paw + LLLT), A4 (carrageenan-1.0 mg/paw), and A5 (carrageenan-1.0 mg/paw + LLLT). The animals from groups A3 and A5 were irradiated 1 h after induction of inflammation by carrageenan injection. Continuous-wave red laser with wavelengths of 660 nm and dose of 7.5 J/cm(2) was used. Six hours after carrageenan-induced inflammation, mPGES-1 and prostacyclin receptor (IP) mRNA expression were significantly increased both in subplantar and brain tissues. LLLT was able to reduce both mPGES-1 and IP mRNA expression in subplantar and brain tissues. We suggest that LLLT is able to reduce both inflammation and hyperalgesia observed in the model of edema formation and hyperalgesia induced by carrageenan, by a mechanism involving the decrease in the expression of both mPGES-1 and IP.
Assuntos
Encéfalo/metabolismo , Edema/radioterapia , Membro Posterior/metabolismo , Oxirredutases Intramoleculares/genética , Lasers Semicondutores/uso terapêutico , Terapia com Luz de Baixa Intensidade , Receptores de Prostaglandina/metabolismo , Animais , Encéfalo/imunologia , Encéfalo/efeitos da radiação , Carragenina , Regulação para Baixo , Edema/induzido quimicamente , Edema/metabolismo , Pé/patologia , Pé/efeitos da radiação , Expressão Gênica/efeitos da radiação , Membro Posterior/patologia , Membro Posterior/efeitos da radiação , Hiperalgesia/metabolismo , Hiperalgesia/radioterapia , Oxirredutases Intramoleculares/metabolismo , Masculino , Prostaglandina-E Sintases , RNA Mensageiro/metabolismo , Ratos , Ratos Wistar , Receptores de Prostaglandina/genéticaRESUMO
Persistent pains associated with inflammatory and neuropathic states are prevalent and debilitating diseases, which still remain without a safe and adequate treatment. Euphol, an alcohol tetracyclic triterpene, has a wide range of pharmacological properties and is considered to have anti-inflammatory action. Here, we assessed the effects and the underlying mechanisms of action of euphol in preventing inflammatory and neuropathic pain. Oral treatment with euphol (30 and 100 mg/kg) reduced carrageenan-induced mechanical hyperalgesia. Likewise, euphol given through the spinal and intracerebroventricular routes prevented mechanical hyperalgesia induced by carrageenan. Euphol consistently blocked the mechanical hyperalgesia induced by complete Freund's adjuvant, keratinocyte-derived chemokine, interleukin-1ß, interleukin-6 and tumor necrosis factor-alpha associated with the suppression of myeloperoxidase activity in the mouse paw. Oral treatment with euphol was also effective in preventing the mechanical nociceptive response induced by ligation of the sciatic nerve and also significantly reduced the levels and mRNA of cytokines/chemokines in both paw and spinal cord tissues following i.pl. injection of complete Freund's adjuvant. In addition, the pre-treatment with either CB1R or CB2R antagonists, as well as the knockdown gene of the CB1R and CB2R, significantly reversed the antinociceptive effect of euphol. Interestingly, even in higher doses, euphol did not cause any relevant action in the central nervous system. Considering that few drugs are currently available for the treatment of chronic pain states, the present results provided evidence that euphol constitutes a promising molecule for the management of inflammatory and neuropathic pain states.
Assuntos
Anti-Inflamatórios não Esteroides/uso terapêutico , Edema/prevenção & controle , Hiperalgesia/prevenção & controle , Lanosterol/análogos & derivados , Neuralgia/prevenção & controle , Receptor CB1 de Canabinoide/metabolismo , Receptor CB2 de Canabinoide/metabolismo , Animais , Anti-Inflamatórios não Esteroides/administração & dosagem , Anti-Inflamatórios não Esteroides/antagonistas & inibidores , Anti-Inflamatórios não Esteroides/farmacologia , Comportamento Animal/efeitos dos fármacos , Citocinas/genética , Citocinas/metabolismo , Relação Dose-Resposta a Droga , Regulação para Baixo/efeitos dos fármacos , Edema/imunologia , Edema/metabolismo , Técnicas de Silenciamento de Genes , Membro Posterior/efeitos dos fármacos , Membro Posterior/metabolismo , Hiperalgesia/imunologia , Hiperalgesia/metabolismo , Lanosterol/administração & dosagem , Lanosterol/antagonistas & inibidores , Lanosterol/farmacologia , Lanosterol/uso terapêutico , Masculino , Camundongos , Neuralgia/imunologia , Neuralgia/metabolismo , Infiltração de Neutrófilos/efeitos dos fármacos , Medição da Dor , RNA Mensageiro/metabolismo , Receptor CB1 de Canabinoide/antagonistas & inibidores , Receptor CB1 de Canabinoide/genética , Receptor CB2 de Canabinoide/antagonistas & inibidores , Receptor CB2 de Canabinoide/genética , Medula Espinal/efeitos dos fármacos , Medula Espinal/metabolismoRESUMO
Purpose: Angiogenesis involves many mediators including integrins, and the tripeptide RGD is a target amino acid recognition sequence for many of them. Hindlimb ischemia is a simple and convenient animal model however standardization of the injection procedures in the devascularized and control limb is lacking, thus rendering difficult the interpretation of results. The aim of this investigations was to evaluate neovascularization in a hindlimb murine model by means of 99mTc-HYNIC-ß-Ala-RGD. Methods: 99mTc-HYNIC-RGD analog was prepared using coligands. Ischemia was induced in Wistar rats by double- ligation of the common femoral artery. Radiolabeled RGD was injected after 2h, as well as 1, 3, 5, 7, 10 and 14 days. Uptake was evaluated by planar imaging and biodistribution studies. Results: The highest ratio between ischemia and control was achieved at the 7th day (2.62 ± 0.95), with substantial decrease by the 14th day. For pertechnetate the 7th day ratio was 0.87 ± 0.23. Scintigraphic image confirmed different uptakes. Conclusion: 99mTc-HYNIC-RGD analog concentrated in ischemic tissue by the time of widespread angiogenesis and pertechnetate confirmed reduction in blood flow. In this sense, the protocol can be recommended for ischemic models.
Objetivo: A angiogênese em resposta a fenômenos isquêmicos envolve vários mediadores como as integrinas, sendo que o tripeptídeo RGD possui uma seqüência de aminoácidos com reconhecimento para este alvo. O modelo animal de isquemia de pata traseira é simples e conveniente, porém não há uma padronização do procedimento de injeção e controle radioisotópico em membro desvascularizado, dificultando, portanto a interpretação de resultados. O objetivo deste estudo foi avaliar a neovascularização em modelo murino de isquemia de pata traseira através do radiotraçador 99mTc-HYNIC-ß-Ala-RGD. Métodos: O análogo 99mTc-HYNIC-RGD foi preparado usando coligantes. A isquemia foi induzida em ratos Wistar por dupla-ligação da artéria femoral comum na prega inguinal. Peptídeo RGD radiomarcado foi injetado após 2h, assim como 1, 3, 5, 7, 10 e 14 dias. A captação foi avaliada por imagem planar e estudos de biodistribuição. Resultados: A maior diferença de captação entre isquemia e pata controle foi obtida no 7º dia (2,62 ± 0,95), com decréscimo acentuado no 14º dia. Para o pertecnetato a razão no 7º dia foi 0,87 ± 0,23. A imagem cintilográfica confirmou as diferentes captações. Conclusões: O análogo 99mTc-HYNIC-RGD concentrou-se no tecido isquêmico na etapa em que a angiogênese é mais acentuada, e o estudo do pertecnetato confirmou a redução no fluxo sanguíneo. Desta maneira, este protocolo diagnóstico pode ser recomendado para modelos isquêmicos.
Assuntos
Animais , Masculino , Ratos , Membro Posterior/irrigação sanguínea , Isquemia/fisiopatologia , Neovascularização Fisiológica/fisiologia , Compostos de Organotecnécio , Compostos Radiofarmacêuticos , Sequência de Aminoácidos , Sequência Conservada , Membro Posterior/metabolismo , Membro Posterior , Isquemia , Oligopeptídeos , Compostos de Organotecnécio/farmacocinética , Ratos Wistar , Compostos Radiofarmacêuticos/farmacocinética , Distribuição TecidualRESUMO
PURPOSE: Angiogenesis involves many mediators including integrins, and the tripeptide RGD is a target amino acid recognition sequence for many of them. Hindlimb ischemia is a simple and convenient animal model however standardization of the injection procedures in the devascularized and control limb is lacking, thus rendering difficult the interpretation of results. The aim of this investigations was to evaluate neovascularization in a hindlimb murine model by means of 99(m)Tc-HYNIC-ß-Ala-RGD. METHODS: 99(m)Tc-HYNIC-RGD analog was prepared using coligands. Ischemia was induced in Wistar rats by double- ligation of the common femoral artery. Radiolabeled RGD was injected after 2h, as well as 1, 3, 5, 7, 10 and 14 days. Uptake was evaluated by planar imaging and biodistribution studies. RESULTS: The highest ratio between ischemia and control was achieved at the 7th day (2.62 ± 0.95), with substantial decrease by the 14th day. For pertechnetate the 7th day ratio was 0.87 ± 0.23. Scintigraphic image confirmed different uptakes. CONCLUSION: 99(m)Tc-HYNIC-RGD analog concentrated in ischemic tissue by the time of widespread angiogenesis and pertechnetate confirmed reduction in blood flow. In this sense, the protocol can be recommended for ischemic models.
Assuntos
Membro Posterior/irrigação sanguínea , Isquemia/fisiopatologia , Neovascularização Fisiológica/fisiologia , Compostos de Organotecnécio , Compostos Radiofarmacêuticos , Sequência de Aminoácidos , Animais , Sequência Conservada , Membro Posterior/diagnóstico por imagem , Membro Posterior/metabolismo , Isquemia/diagnóstico por imagem , Masculino , Oligopeptídeos , Compostos de Organotecnécio/farmacocinética , Cintilografia , Compostos Radiofarmacêuticos/farmacocinética , Ratos , Ratos Wistar , Distribuição TecidualRESUMO
This study assessed the possible antinociceptive role of peripheral 5-HT(1) receptor subtypes in the rat formalin test. Rats were injected into the dorsum of the hind paw with 50 microl of diluted formalin (1%). Nociceptive behavior was quantified as the number of flinches of the injected paw. Reduction of flinching was considered as antinociception. Ipsilateral, but not contralateral, peripheral administration of the 5-HT(1) receptor agonists R(+)-UH-301 (5-HT(1A); 0.1-3 microg/paw), CGS-12066A (5-HT(1B); 0.01-0.3 microg/paw), GR46611 (5-HT(1B/1D); 0.3-10 microg/paw), BRL54443 (5-HT(1E/1F); 3-300 microg/paw) or LY344864 (5-HT(1F); 3-300 microg/paw) significantly reduced formalin-induced flinching. The corresponding vehicle was devoid of any effect by itself. The local antinociceptive effect of R(+)-UH-301 (0.3 microg/paw) was significantly reduced by WAY-100635 (30-100 microg/paw; a 5-HT(1A) receptor antagonist). Moreover, the antagonists GR55562 (30-100 microg/paw; 5-HT(1B/D)) or SB224289 (30-100 microg/paw; 5-HT(1B)) dose-dependently reduced the antinociceptive effect of CGS-12066A (0.3 microg/paw) whereas GR55562 (30-100 microg/paw) or BRL15572 (30-100 microg/paw, 5-HT(1D)) reduced the antinociceptive effect of GR46611 (0.3 microg/paw). Interestingly, the effects of BRL54443 and LY344864 (300 microg/paw each) were partially reduced by methiothepin, but not by the highest doses of WAY-100635, SB224289 or BRL15572. The above antagonists did not produce any effect by themselves. These results suggest that peripheral activation of the 5-HT(1A,) 5-HT(1B), 5-HT(1D), 5-HT(1F) and, probably, 5-HT(1E) receptor subtypes leads to antinociception in the rat formalin test. Thus, the use of selective 5-HT(1) receptor agonists could be a therapeutic strategy to reduce inflammatory pain.
Assuntos
Dor/tratamento farmacológico , Dor/metabolismo , Nervos Periféricos/efeitos dos fármacos , Nervos Periféricos/metabolismo , Receptores de Serotonina/metabolismo , Agonistas do Receptor de Serotonina/farmacologia , Animais , Relação Dose-Resposta a Droga , Feminino , Formaldeído , Lateralidade Funcional , Membro Posterior/efeitos dos fármacos , Membro Posterior/metabolismo , Dor/induzido quimicamente , Medição da Dor , Ratos , Ratos Wistar , Receptor 5-HT1A de Serotonina/metabolismo , Receptor 5-HT1B de Serotonina/metabolismo , Receptor 5-HT1D de Serotonina/metabolismo , Agonistas do Receptor 5-HT1 de Serotonina , Agonistas do Receptor de Serotonina/administração & dosagem , Receptor 5-HT1F de SerotoninaRESUMO
The anti-inflammatory activities of some medicinal plants are attributed to their contents of sesquiterpene lactones. In the present study, the anti-inflammatory and anti-nociceptive activity of a sesquiterpene lactone isolated from Viguiera robusta, budlein A in mice was investigated. The treatment with budlein A dose--(1.0-10.0 mg/kg, p.o., respectively) dependently inhibited the carrageenan-induced: i. neutrophil migration to the peritoneal cavity (2-52%), ii. neutrophil migration to the paw skin tissue (32-74%), iii. paw oedema (13-74%) and iv. mechanical hypernociception (2-58%) as well as the acetic acid-induced writhings (0-66%). Additionally, budlein A (10.0 mg/kg) treatment inhibited the mechanical hypernociception-induced by tumour necrosis factor (TNF-alpha, 36%), Keratinocyte-derived chemokine (KC, 37%) and Interleukin-1beta (IL-1beta, 28%), but not of prostaglandin E(2) or dopamine. Budlein A also inhibited the carrageenan-induced release of TNF-alpha (52%), KC (70%) and IL-1beta (59%). Furthermore, an 8 days treatment with budlein A inhibited Complete Freund's adjuvant (10 microl/paw)-induced hypernociception, paw oedema and paw skin myeloperoxidase activity increase while not affecting the motor performance or myeloperoxidase activity in the stomach. Concluding, the present data suggest that budlein A presents anti-inflammatory and antinociceptive property in mice by a mechanism dependent on inhibition of cytokines production. It supports the potential beneficial effect of orally administered budlein A in inflammatory diseases involving cytokine-mediated nociception, oedema and neutrophil migration.
Assuntos
Analgésicos/farmacologia , Citocinas/metabolismo , Lactonas/farmacologia , Sesquiterpenos/farmacologia , Analgésicos/química , Animais , Anti-Inflamatórios/química , Anti-Inflamatórios/farmacologia , Asteraceae/química , Comportamento Animal/efeitos dos fármacos , Carragenina/toxicidade , Movimento Celular/efeitos dos fármacos , Dinoprostona/toxicidade , Dopamina/toxicidade , Relação Dose-Resposta a Droga , Edema/induzido quimicamente , Edema/prevenção & controle , Adjuvante de Freund/toxicidade , Membro Posterior/efeitos dos fármacos , Membro Posterior/metabolismo , Membro Posterior/patologia , Inflamação/induzido quimicamente , Inflamação/prevenção & controle , Lactonas/química , Masculino , Camundongos , Estrutura Molecular , Neutrófilos/efeitos dos fármacos , Neutrófilos/patologia , Dor/induzido quimicamente , Dor/fisiopatologia , Dor/prevenção & controle , Cavidade Peritoneal/patologia , Sesquiterpenos/química , Transdução de Sinais/efeitos dos fármacos , Pele/efeitos dos fármacos , Pele/metabolismo , Pele/patologiaRESUMO
We investigated the contribution of neutrophils to joint hyperalgesia and peroxynitrite formation in zymosan arthritis. Rats received 1 mg zymosan intra-articular, and joint hyperalgesia was measured using the rat knee-joint articular incapacitation test. After 6 h, joint exudates were collected by aspiration for the assessment of cell influx, myeloperoxidase activity, and nitrite (as an index of nitric oxide formation) levels. Nitrotyrosine content, used as an index of peroxynitrite formation, was measured in joint exudates, using enzyme-linked immunosorbent assay. A group of rats was rendered neutropenic through the administration of a rabbit anti-rat neutrophil antibody (2 ml kg(-1), i.p.) 30 min before injection of 1 mg zymosan intra-articular. Other groups received uric acid (100 or 250 mg kg(-1), i.p.), the peroxynitrite scavenger, 30 min before 1 mg zymosan intra-articular. Controls received the vehicle. The significant inhibition of joint hyperalgesia in neutropenic animals was associated to significantly decreased cell influx, myeloperoxidase activity, nitric oxide, and nitrotyrosine levels in the joint exudates, as compared to naive rats. Uric acid administration inhibited both hyperalgesia and cell influx, as compared to controls. Neutrophils are involved in both nitric oxide and peroxynitrite formation in zymosan arthritis, thereby contributing to acute joint hyperalgesia. Scavenging of reactive nitrogen species (e.g. peroxynitrite) inhibits neutrophil migration and joint hyperalgesia in the acute phase of zymosan arthritis in rats.
Assuntos
Artrite Experimental/metabolismo , Hiperalgesia/metabolismo , Neutrófilos/metabolismo , Ácido Peroxinitroso/metabolismo , Zimosan/toxicidade , Doença Aguda , Animais , Artrite Experimental/induzido quimicamente , Membro Posterior/metabolismo , Membro Posterior/patologia , Hiperalgesia/sangue , Injeções Intra-Articulares , Articulação do Joelho/efeitos dos fármacos , Articulação do Joelho/metabolismo , Articulação do Joelho/patologia , Masculino , Óxido Nítrico/metabolismo , Peroxidase/metabolismo , Ratos , Ratos Wistar , Espécies Reativas de Nitrogênio/metabolismo , Líquido Sinovial/metabolismo , Tirosina/análogos & derivados , Tirosina/metabolismo , Ácido Úrico/administração & dosagem , Ácido Úrico/sangue , Zimosan/administração & dosagemRESUMO
O objetivo do estudo foi avaliar o efeito da etimulação elétrica (EE) no perfil metabólico e no peso muscular de membro posterior de ratos durante a imobilização e após a retirada da órtese...
This study aimed at assessing the effect of electrical stimulation (ES) in muscles metabolic profile and weight of rat hindlimb during the limb immobilization period and after casts were removed...
Assuntos
Animais , Ratos , Estimulação Elétrica , Imobilização , Membro Posterior/metabolismoRESUMO
The aim of this study was to evaluate the effect of angiotensin II on models of acute inflammation. This study shows that angiotensin II potentiates the carrageenan- and dextran-induced paw edema. The administration of angiotensin II does not change the myeloperoxidase activity, neither the tissue content of interleukin-1 beta and tumor necrosis alpha nor the neutrophil migration to the peritoneal cavity, but induces significant enhancement of mast cell degranulation. The anti-histamine, mepyramine, and the anti-serotonin, metisergyde, reduce the angiotensin II-facilitated dextran-induced edema. Our results suggest that angiotensin II increases the vascular permeability through induction of mast cell degranulation and that this effect is mediated by the angiotensin AT2 receptor, since the angiotensin AT1 receptor antagonist and the angiotensin AT2 receptor agonist potentiated the paw edema.
Assuntos
Angiotensina II/toxicidade , Inflamação/induzido quimicamente , Mastócitos/fisiologia , Doença Aguda , Animais , Antialérgicos/farmacologia , Carragenina/toxicidade , Degranulação Celular/efeitos dos fármacos , Movimento Celular/efeitos dos fármacos , Dextranos/toxicidade , Sinergismo Farmacológico , Edema/induzido quimicamente , Edema/metabolismo , Edema/prevenção & controle , Membro Posterior/efeitos dos fármacos , Membro Posterior/metabolismo , Membro Posterior/patologia , Inflamação/patologia , Inflamação/fisiopatologia , Interleucina-1beta/metabolismo , Neutrófilos/efeitos dos fármacos , Neutrófilos/patologia , Cavidade Peritoneal/patologia , Peroxidase/metabolismo , Pirilamina/farmacologia , Ratos , Ratos Wistar , Fatores de Tempo , Fator de Necrose Tumoral alfa/metabolismo , Vasoconstritores/toxicidadeRESUMO
Statins (3-hydroxy-3-methylglutaryl-CoA reductase inhibitors) are used in the treatment of hypercholesterolemic patients to reduce risk of cardiovascular diseases because of their cholesterol lowering action. Other lipid independent protective actions of statins have been reported. However, some adverse side effects have, also, been described. We report, here, that liver mitochondria isolated from hypercholesterolemic LDL receptor knockout mice treated during 15 days with therapeutic doses (100 mg/kg, p.o.) of lovastatin presented a higher susceptibility to develop membrane permeability transition (MPT). In experiments in vitro, lovastatin-induced MPT in a dose-dependent manner (10-80 microM) by a mechanism sensitive to cyclosporin A (cyclophilin sequestrant), dithiothreitol (reducing agent), adenine nucleotide carrier inhibitor (ADP), catalase (H2O2 reductant) and EGTA (calcium chelator). In agreement with the inhibition of the mitochondrial swelling by dithiothreitol, lovastatin, also, decreased the content of total mitochondrial membrane protein thiol groups. Simvastatin had similar effects on mitochondria; however, pravastatin, a hydrophilic statin, had a weaker effect in inducing MPT. In conclusion, statins can act directly on mitochondria either in vivo or in vitro inducing permeability transition, which is a process involved in cell death.
Assuntos
Inibidores de Hidroximetilglutaril-CoA Redutases/farmacologia , Mitocôndrias Hepáticas/efeitos dos fármacos , Mitocôndrias Musculares/efeitos dos fármacos , Difosfato de Adenosina/farmacologia , Animais , Catalase/farmacologia , Quelantes/farmacologia , Colesterol/sangue , Ditiotreitol/farmacologia , Ácido Egtázico/farmacologia , Eletrofisiologia , Membro Posterior/metabolismo , Técnicas In Vitro , Lovastatina/farmacologia , Camundongos , Camundongos Knockout , Dilatação Mitocondrial/efeitos dos fármacos , Permeabilidade/efeitos dos fármacos , Fenazinas , Proteínas/metabolismo , Receptores de LDL/genética , Compostos de Sulfidrila/metabolismo , Reagentes de Sulfidrila/farmacologiaRESUMO
OBJETIVO: Investigar alterações dos parâmetros metabólicos no sangue e rim de ratos submetidos à isquemia/reperfusão do membro pélvico. MÉTODOS: Quarenta e oito ratos machos foram distribuídos aleatoriamente em 2 grupos pré-tratados com administração intragástrica de solução salina 2,0 mL (G-1) ou L-alanil-glutamina 0,75 mgKg-1(G-2), uma vez ao dia (7:00h) durante 7 dias. Uma hora após a última gavagem todos os ratos foram anestesiados com éter dietílico, laparotomizados e submetidos ao pinçamento da artéria de ilíaca esquerda, durante 3 horas. Amostras foram coletadas ao término de isquemia e durante a reperfusão (1-3-6h) para determinação das concentrações in vivo de piruvato, lactato, glicose e corpos cetônicos (rim e sangue) e ATP (rim). RESULTADOS: Lactacemia e cetonemia aumentaram no grupo G-2 quando comparadas às aferidas em ratos não-tratados, durante a reperfusão. As concentrações de piruvato diminuíram e de lactato aumentaram significativamente no rim, durante a reperfusão (1h, 3h) em ratos do G-2 comparados aos respectivos controles. Houve um aumento significante nas concentrações renais de glicose, ATP e corpos cetônicos nos ratos tratados com L-alanil-glutamina durante a reperfusão (3h). CONCLUSÕES: A isquemia do membro pélvico em ratos pré-tratados com L-alanil-glutamina induz aumento da lactacemia e da concentração de lactato renal, indicando atividade glicolítica aumentada na medula renal. A hipercetonemia induzida pela oferta do dipeptídeo sugere cetogênese elevada, sinalizada por possível queda nas concentrações plasmáticas de insulina resultante da maior oxidação de glicose e utilização desse hormônio em tecidos periféricos.
Assuntos
Animais , Masculino , Ratos , Dipeptídeos/farmacologia , Membro Posterior/irrigação sanguínea , Rim/efeitos dos fármacos , Traumatismo por Reperfusão/metabolismo , Ácido Láctico/sangue , Ácido Pirúvico/sangue , Cetonas/sangue , Modelos Animais de Doenças , Glicemia/análise , Isquemia/etiologia , Isquemia/metabolismo , Membro Posterior/metabolismo , Distribuição Aleatória , Ratos Wistar , Rim/metabolismo , Estatísticas não Paramétricas , Traumatismo por Reperfusão/sangueRESUMO
PURPOSE: To investigate the effects of l-alanyl-glutamine (Ala-Gln) intragastric administration upon blood and kidney metabolic parameters alterations in rats subjected to ischemia/reperfusion of hind limb. METHODS: Forty-eight male rats were randomized in 2 groups offered via gavage either saline 2.0 mL (G-1) or Ala-Gln solution 0.75 mgKg-1(G-2) once a day at 7 AM during 7 days. One-hour after the last gavage (Day 7) all rats were submitted to ether anesthesia, laparotomy and clamping of the left iliac artery for 3 h. Kidney and blood samples were collected at the end of ischemic period (3 h) and at 1-3-6 h during reperfusion period for metabolites (pyruvate, lactate, glucose and ketone bodies) enzymatic analysis. ATP was also assayed in kidney samples. RESULTS: Lactacemia and ketonemia were significantly increased in Ala-Gln treated rats during reperfusion. Kidney pyruvate concentrations were significantly decreased and tissue lactate concentrations were significantly increased during reperfusion (1 h and 3 h) in G-2 rats compared with respective controls. Glucose, ATP and ketone bodies concentrations were significantly increased in the kidney in L-Ala-Gln treated rats at 3 hours after reperfusion as compared to respective controls. CONCLUSIONS: Unilateral hind limb ischemia in L-Ala-Gln pre-treated rats may induce increased lactacemia and increased kidney lactate concentrations, indicating increased glycolytic activity in renal medulla and in other peripheral tissues. Higher ketonemia during reperfusion may reflect a possible increase in ketogenesis due to lower insulin plasma concentration hepatic signaling as a result of increased glucose oxidation in peripheral tissues, caused by the intra-gastric administration of glutamine dipeptide, suggesting also decreased insulin resistance.
Assuntos
Dipeptídeos/farmacologia , Membro Posterior/irrigação sanguínea , Rim/efeitos dos fármacos , Traumatismo por Reperfusão/metabolismo , Animais , Glicemia/análise , Modelos Animais de Doenças , Membro Posterior/metabolismo , Isquemia/etiologia , Isquemia/metabolismo , Cetonas/sangue , Rim/metabolismo , Ácido Láctico/sangue , Masculino , Ácido Pirúvico/sangue , Distribuição Aleatória , Ratos , Ratos Wistar , Traumatismo por Reperfusão/sangue , Estatísticas não ParamétricasRESUMO
In previous experiments, it was observed that in the perfused hind-limb of phosphorus deficient rats there was a faster utilization of glucose when compared with preparations obtained from ad-libitum fed rats but similar to that obtained from pair-weighed rats. A greater release of lactate under the influence of insulin and a marked spontaneous and insulin induced liberation of pyruvate was registered in the perfused hind-limb of the phosphorus deficient rat. Since a hypophosphatemic medium was employed, we though it would be interesting to study the effect of low perfusate Pi in normal rat hind-limb preparations and, additionally, to observe it fast changes in the level of medium orthophosphate from normal to low values and viceversa were able to determine changes in glucose uptake and lactate and pyruvate release. In one group of experiments, the hind-limb of normal rats was perfused successively with orthophosphate deprived medium for thirty minutes in each stage. In another group of experiments, the first stage was carried out with normal. Pi medium, the second with orthophosphate deprived medium, and the third with normal Pi medium; each stage lasted thirty minutes. In all the experiments there was a gradual release of orthophosphate. The glucose uptake was not modified by the fast changes in the medium Pi nor were significant differences in lactate and pyruvate release observed, which showed clear increases in all stages. It is concluded that hypophosphatemia alone is not sufficient to obtain greater increases of lactate and pyruvate release; it is also required that the hind-limb preparations be obtained from ..