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1.
Bol. latinoam. Caribe plantas med. aromát ; 20(3): 303-314, may. 2021. tab, ilus
Artigo em Inglês | LILACS | ID: biblio-1343478

RESUMO

In this study, against streptozotocin (STZ) induced diapetic nephropathy (DN); it is aimed to investigate the use of thymoquinone (TQ) and ß-aminoisobutyric acid (BAIBA) and to compare the effects of these agents. With random selection of 35 male rats, five groups (seven rats in each group) were constituted as follows: Control, STZ, STZ + TQ, STZ + BAIBA, STZ + TQ + BAIBA. In the STZ group; body weight, glutathione (GSH) and insulin levels decreased, relative kidney weight, malondialdehyde (MDA), glucose, blood urea nitrogen (BUN) and creatinine (Cr) levels were increased. Also, in kidney tissue; histopathological changes (such as thickening of the capsular, glomerular and tubular basement membranes, increased mesangial matrix amount, increased cytoplasmic vacuolization in some of the tubular epithelial cells, increased tumor necrosis factor-alpha (TNF-α) expression, and inflammatory cell infiltrations in interstitial tissue) were detected. It was observed that these changes occurring after diabetes mellitus (DM) reversed significantly in TQ, BAIBA and TQ + BAIBA groups.


En este estudio, contra la nefropatía diapética (ND) inducida por estreptozotocina (STZ); tiene como objetivo investigar el uso de timoquinona (TQ) y ácido ß-aminoisobutírico (BAIBA) y comparar los efectos de estos agentes. Con la selección aleatoria de 35 ratas macho, se constituyeron cinco grupos (siete ratas en cada grupo) como sigue: Control, STZ, STZ + TQ, STZ + BAIBA, STZ + TQ + BAIBA. En el grupo STZ; el peso corporal, los niveles de glutatión (GSH) y de insulina disminuyeron, el peso relativo de los riñones, el malondialdehído (MDA), la glucosa, el nitrógeno ureico en sangre (BUN) y los niveles de creatinina (Cr) aumentaron. Además, en tejido renal; se detectaron cambios histopatológicos (como engrosamiento de las membranas basales capsular, glomerular y tubular, aumento de la cantidad de matriz mesangial, aumento de la vacuolización citoplasmática en algunas de las células epiteliales tubulares, aumento de la expresión del factor de necrosis tumoral alfa (TNF-α) e infiltraciones de células inflamatorias en tejido intersticial). Se observó que estos cambios que ocurren después de la diabetes mellitus (DM) se revirtieron significativamente en los grupos TQ, BAIBA y TQ + BAIBA.


Assuntos
Animais , Masculino , Ratos , Benzoquinonas/administração & dosagem , Nefropatias Diabéticas/tratamento farmacológico , Ácidos Aminoisobutíricos/administração & dosagem , Nitrogênio da Ureia Sanguínea , Peso Corporal , Imuno-Histoquímica , Ratos Sprague-Dawley , Estreptozocina , Estresse Oxidativo , Creatinina/análise , Modelos Animais de Doenças , Glucose/análise , Glutationa/análise , Rim/efeitos dos fármacos
2.
Int. j. morphol ; 39(2): 469-476, abr. 2021. ilus, graf
Artigo em Inglês | LILACS | ID: biblio-1385371

RESUMO

SUMMARY: Renal ischemia-reperfusion injury (IRI)is an unavoidable consequence in renal transplantation and multiple clinical settings. A debate has been raised about the particular role of hypoxia-inducible factor (HF-1α) in the renal injury pathogenesis and the renal cortex ultrastructural alterations. Also, we investigated the antioxidant/anti-inflammatory effect of thymoquinone and its modulatory role on HIF-1α in protection against renal IRI.Adult male Wister albino rats were assigned into 3 groups (n=16); 1) Sham-operated, 2) IRI model and 3) renal IRI pre-treated with thymoquinone 10 mg.kg-1.day-1 (TQ-IRI) for 10 days and at the reperfusion onset. Following the operation, 8 rats from each group were euthanized after 3 hours and the remaining 8 rats at 24 hours. Renal injury was assessed by the increased blood urea nitrogen, creatinine level, and the EGTI histological injury scoreat both 3 and 24h. HIF-1α was upregulated (p<0.01) and was correlated with renal tissue reactive oxygen species (ROS) production and total oxidant capacity (TAC) consumption. Elevated inflammatory markers (NFkB, MCP-1 and VCAM-1) were associated with renal IRI.Thymoquinone treatment inhibited the accumulation of HIF-1α (p<0.01), reduced renal oxidation/inflammation process and markedly diminished renal injury.


RESUMEN: La lesión por isquemia-reperfusión renal (IRR) es una consecuencia inevitable en el trasplante renal como también en múltiples contextos clínicos. Se ha suscitado una discusión referente a la relación particular del factor inducible por hipoxia (HF- 1α) en la patogénesis de la lesión renal y las alteraciones ultraestructurales de la corteza renal. Además, investigamos el efecto antioxidante / antiinflamatorio de la timoquinona y su papel modulador sobre HIF-1α en la protección contra IRR. Se utilizaron ratas albinas Wister macho adultas divididas en 3 grupos (n = 16); 1) Intervención simulada, 2) modelo IRR y 3) IRR pretratado con timoquinona 10 mg/kg-1. día-1 (TQ-IRR) durante 10 días y al inicio de la reperfusión. Posterior a la operación, 8 ratas de cada grupo fueron sacrificadas después de 3 horas y las 8 ratas restantes a las 24 horas. La lesión renal se evaluó por el aumento de nitrógeno ureico en sangre, el nivel de creatinina y la puntuación de lesión histológica EGTI tanto a las 3 como a las 24 horas. HIF-1α se incrementó (p <0,01) y se correlacionó con la producción de especies de oxígeno reactivo (ROS) del tejido renal y el consumo de capacidad oxidante total. Los marcadores inflamatorios elevados (NFkB, MCP-1 y VCAM-1) se asociaron con IRR. El tratamiento con timoquinona inhibió la acumulación de HIF-1α (p <0,01), redujo el proceso de oxidación / inflamación renal y disminuyó notablemente la lesión renal.


Assuntos
Animais , Masculino , Ratos , Traumatismo por Reperfusão/tratamento farmacológico , Benzoquinonas/uso terapêutico , Injúria Renal Aguda/tratamento farmacológico , Ratos Wistar , Estresse Oxidativo , Fator 1 Induzível por Hipóxia/antagonistas & inibidores , Anti-Inflamatórios/uso terapêutico , Antioxidantes/uso terapêutico
3.
Acta cir. bras ; 35(1): e202000105, 2020. tab, graf
Artigo em Inglês | LILACS | ID: biblio-1088523

RESUMO

Abstract Purpose To investigate whether heat shock protein 90 (HSP90) is involved in complement regulation in ischemic postconditioning (IPC). Methods The left coronary artery of rats underwent 30 min of occlusion, followed by 120 min of reperfusion and treatment with IPC via 3 cycles of 30s reperfusion and 30s occlusion. The rats were injected intraperitoneally with 1 mg/kg HSP90 inhibitor geldanamycin (GA) after anesthesia. Eighty rats were randomly divided into four groups: sham, ischemia-reperfusion (I/R), IPC and IPC + GA. Myocardial infarct size, apoptosis index and the expression of HSP90, C3, C5a, tumor necrosis factor (TNF)-alpha, interleukin (IL)-1β and c-Jun N-terminal kinase (JNK) were assessed. Results Compared with the I/R injury, the IPC treatment significantly reduced infarct size, release of troponin T, creatine kinase-MB, and lactate dehydrogenase, and cardiomyocyte apoptosis. These beneficial effects were accompanied by a decrease in TNF-α, IL-1β, C3, C5a and JNK expression levels. However, all these effects were abrogated by administration of the HSP90 inhibitor GA. Conclusion HSP90 exerts a profound effect on IPC cardioprotection, and may be linked to the inhibition of the complement system and JNK, ultimately attenuating I/R-induced myocardial injury and apoptosis.


Assuntos
Animais , Ratos , Proteínas do Sistema Complemento/metabolismo , Traumatismo por Reperfusão Miocárdica/metabolismo , Benzoquinonas/farmacologia , Proteínas de Choque Térmico HSP90/antagonistas & inibidores , Lactamas Macrocíclicas/farmacologia , Proteínas Quinases JNK Ativadas por Mitógeno/metabolismo , Infarto do Miocárdio/metabolismo , RNA Mensageiro/metabolismo , Distribuição Aleatória , Fator de Necrose Tumoral alfa/metabolismo , Ratos Sprague-Dawley , Mediadores da Inflamação , Creatina Quinase Forma MB/metabolismo , Pós-Condicionamento Isquêmico/métodos
4.
Int. j. morphol ; 36(2): 519-522, jun. 2018. graf
Artigo em Inglês | LILACS | ID: biblio-954147

RESUMO

Methotrexate drug is commonly used to treat cancer; it is known to cause reproductive damage. Thymoquinone, as a natural component of herbs has many healthy benefits shown in researches. The present study aimed to investigate probable therapeutic effects of Thymoquinone against Methotrexate-induced damage on sperm parameters in mice. In this experimental study, 30 male mice (25-30 g) were divided into five groups of six in each group. The mice were received normal saline (control group), Methotrexate (20 mg/kg), Methotrexate (20 mg/kg) + Thymoquinone (2, 10 and 20 mg/kg) by intraperitoneal injection. On the day after the last injection, the sperm parameters including motility, viability and count of sperms were assessed. Data analysis was performed using one-way ANOVA followed by Tukey test. Methotrexate alone showed a significant reduction in sperm parameters compared to the control group (P=0.00). In groups treated with Methotrexate and Thymoquinone, sperm parameters (motility ,viability, count sperm) did not show any significant differences with control group (P=0.00). Thymoquinone, as a potent antioxidant, could compensate for the toxicity induced by Methotrexate. These medical trends may be useful for diminishing the side effects of Methotrexate on the male reproductive system.


El metotrexato es un fármaco utilizado comúnmente para tratar el cáncer pero además causa daño en los órganos reproductivos. Durante las investigaciones se ha demostrado que la timoquinona, un componente natural de las hierbas, tiene numerosos beneficios. El objetivo del estudio fue investigar el probable efecto terapéutico de la timoquinona contra el daño inducido por metotrexato, en los parámetros espermáticos en ratones. En este estudio experimental, se dividieron 30 ratones machos (25-30 g) en cinco grupos de seis en cada uno. Los ratones recibieron solución salina normal (grupo control), metotrexato (20 mg / kg), metotrexato (20 mg / kg) + timoquinona (2, 10 y 20 mg / kg) por inyección intraperitoneal. El día después de la última inyección, se evaluaron los parámetros espermáticos, incluida la motilidad, la viabilidad y el recuento de espermatozoides. El análisis de los datos se realizó utilizando test de ANOVA seguido de la prueba de Tukey. Durante el uso exclusivo de metotrexato se observó una reducción significativa en los parámetros espermáticos en comparación con el grupo control (P = 0.00). En los grupos tratados con metotrexato y timoquinona, los parámetros espermáticos (motilidad, viabilidad, conteo de espermatozoides) no mostraron diferencias significativas con el grupo control (P = 0.00). Como potente antioxidante, la timoquinona podría compensar la toxicidad inducida por metotrexato. Estas tendencias médicas pueden ser útiles para disminuir los efectos secundarios de metotrexato en el sistema reproductivo masculino.


Assuntos
Animais , Masculino , Camundongos , Espermatozoides/efeitos dos fármacos , Metotrexato/toxicidade , Benzoquinonas/administração & dosagem , Antineoplásicos/toxicidade , Camundongos Endogâmicos BALB C
5.
Acta cir. bras ; 33(2): 110-116, Feb. 2018. tab, graf
Artigo em Inglês | LILACS | ID: biblio-886264

RESUMO

Abstract Purpose: To investigate thymoquinone, curcumin and a combination of these two drugs were effective or not at the growth of liver. Methods: Forty female Wistar-Albino rats distributed into five groups of eight rats each, control, thymoquinone, curcumin, and thymoquinone/curcumin groups. Pathological specimens were studied using the Ki-67 Proliferation Index(PI); and arginase(Arg), tissue plasminogen activator(tPA), ceruloplasmin(Cer) and nitric oxide(NO) were studied in biochemical analysis. Results: Our results showed that Ki-67 proliferation index was low in Groups 1. The proliferation coefficient was significantly higher in the Group 2 and Group 4 than in the Group 1 and Group 3.(P < 0.001 between Groups 1 and 2, 1 and 4, and 3 and 4). There was no difference between Groups 2 and 4 (P = 1). The results of the biochemical Arg, tPA and Cer test showed statistically between the Group 1 and Group 2. NO showed significant differences Group 1 and 3. Conclusions: Thymoquinone and curcumin both have known positive effects on the organism. Histological and biochemical tests showed that thymoquinone is more effective than curcumin.


Assuntos
Animais , Feminino , Ratos , Regeneração Hepática/efeitos dos fármacos , Antioxidantes/farmacologia , Arginase/sangue , Ceruloplasmina/análise , Biomarcadores/sangue , Benzoquinonas/farmacologia , Transplante de Fígado , Ativador de Plasminogênio Tecidual/sangue , Ratos Wistar , Antígeno Ki-67/análise , Curcumina/farmacologia , Proliferação de Células , Hepatectomia/métodos , Fígado/patologia , Neoplasias Hepáticas/cirurgia , Antineoplásicos/farmacologia , Óxido Nítrico/sangue
6.
Arq. neuropsiquiatr ; 76(1): 32-40, Jan. 2018. graf
Artigo em Inglês | LILACS | ID: biblio-888340

RESUMO

ABSTRACT In this study, the effect of thymoquinone (TQ) on propylthiouracil (PTU)-induced memory impairment was investigated in juvenile rats. The rats were grouped into control, Hypo, Hypo-TQ5 and Hypo-TQ10. Propylthiouracil increased latency time in the Morris water maze test and decreased delay in entering the dark compartment in the passive avoidance test. Both 5 mg/kg and 10 mg/kg doses of TQ decreased latency time in the Morris water maze test and increased delay in entering the dark compartment in a passive avoidance test. The PTU also increased malondialdehyde and nitric oxide metabolites in the brain while reduced the thiol content and superoxide dismutase and catalase activities and serum T4 level. Both doses of TQ decreased malondialdehyde and nitric oxide metabolites in the brain while enhanced the thiol content and superoxide dismutase and catalase activities and serum T4 level. The results of the present study showed that TQ protected against PTU-induced memory impairments in rats.


RESUMO Neste estudo, foi investigado o efeito da timoquinona (TQ) contra deficiências de memória induzidas por propiltiouracilo (PTU) em ratos juvenis. Os ratos foram agrupados em grupos: controle, Hypo, Hypo-TQ5, e Hypo-TQ10. O PTU aumentou o tempo de latência no teste do labirinto aquático de Morris (MWM) e diminuiu o atraso para entrar no compartimento escuro no teste de evasão passiva (PA). Ambas as doses de TQ diminuíram o tempo de latência no teste de MWM e aumentaram o atraso para entrar no compartimento escuro no teste de PA. O PTU também aumentou os metabolitos de malondialdeído (MDA) e óxido nítrico (NO) no cérebro, enquanto reduziu o teor de tiol e as atividades de superóxido dismutasa (SOD) e catalasa (CAT) e o nível sérico de T4. Ambas as doses de TQ diminuíram os metabolitos de MDA e de NO no cérebro, aumentaram o conteúdo de tiol e as atividades de SOD e CAT e o nível de T4 no soro. Os resultados do presente estudo mostraram que a TQ protegeu contra deficiências de memória induzidas por PTU em ratos.


Assuntos
Animais , Masculino , Benzoquinonas/farmacologia , Estresse Oxidativo/efeitos dos fármacos , Hipotireoidismo/complicações , Deficiências da Aprendizagem/tratamento farmacológico , Transtornos da Memória/tratamento farmacológico , Antioxidantes/farmacologia , Propiltiouracila , Aprendizagem da Esquiva/efeitos dos fármacos , Superóxido Dismutase/análise , Antitireóideos , Lesões Encefálicas/metabolismo , Catalase/análise , Ratos Wistar , Aprendizagem em Labirinto/efeitos dos fármacos , Modelos Animais de Doenças , Hipocampo/efeitos dos fármacos , Hipotireoidismo/induzido quimicamente , Deficiências da Aprendizagem/induzido quimicamente , Malondialdeído/análise , Transtornos da Memória/induzido quimicamente , Óxido Nítrico/análise
7.
Acta cir. bras ; 31(4): 271-277, Apr. 2016. tab, graf
Artigo em Inglês | LILACS | ID: lil-781332

RESUMO

PURPOSE: T o investigate the possible protective effect of thymoquinone (TQ) in cisplatin (CP) induced myocardial injury. METHODS: A total of 28 adult male Wistar-Albino rats were randomly and equally divided into four groups as follows: Group 1 (control), Group 2 (CP at 15 mg/kg dose), Group 3 (TQ 40 mg/kg/day for two days prior to CP injection and on third day, CP at 15 mg/kg dose was intraperitoneally administered and TQ treatment continued until fifth day) and Group 4 (TQ at 40mg/kg/day dose for five days). RESULTS: There was a significant increment in CP group in terms of congestion, edema and pycnotic nuclei in myocardial fibers, comparing with other groups. TQ group exhibited significant increase in expression of antiapoptotic protein Bcl-2, comparing with CP group (p<0.05). In only CP administered group, expression of antiapoptotic protein Bcl-2 was lowest comparing with other groups. CONCLUSION: Established data indicate that cisplatin is cardiotoxic and thymoquinone may be useful in treating CP-induced cardiac injury.


Assuntos
Animais , Masculino , Benzoquinonas/farmacologia , Cisplatino/toxicidade , Cardiomiopatias/induzido quimicamente , Cardiomiopatias/prevenção & controle , Antineoplásicos/toxicidade , Antioxidantes/farmacologia , Valores de Referência , Fatores de Tempo , Imuno-Histoquímica , Distribuição Aleatória , Reprodutibilidade dos Testes , Benzoquinonas/uso terapêutico , Resultado do Tratamento , Ratos Wistar , Apoptose/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Proteínas Proto-Oncogênicas c-bcl-2/análise , Proteínas Proto-Oncogênicas c-bcl-2/efeitos dos fármacos , Miócitos Cardíacos/efeitos dos fármacos , Cardiotoxicidade/etiologia , Cardiotoxicidade/patologia , Cardiotoxicidade/prevenção & controle , Coração/efeitos dos fármacos , Cardiomiopatias/patologia , Miocárdio/patologia , Antioxidantes/uso terapêutico
8.
Ciênc. Saúde Colet. (Impr.) ; 20(1): 193-198, jan. 2015. tab
Artigo em Inglês, Português | LILACS | ID: lil-733154

RESUMO

The aim of this study was to applythe Health Belief Model to explain the adherence to the recommendation not to recap needles by dentists and dental assistants of the public health system in a municipality in the State of São Paulo. A questionnaire validated and adapted for the oral health area was used, which included variables related to the frequency of recapping and health beliefs using Likert-type scales. The relationship between beliefs and adherence to the recommendation not to recap needles was obtained by regression analysis. Of all the professionals in this study (n=79), the majority (83.5%) reported recapping needles at least once in the last month. Through regression analysis, it was observed that the relationship between the beliefs described by the model and the attitude whether or not to follow the recommendation not to recap needles was explained by a lower perception of psychological barriers and a greater perception of stimuli not to recap needles. The conclusion reached is that the acceptance of recommendations to prevent working accidents with biological material was explained by some dimensions of the Health Belief Model, enabling discussion about reformulation of training offered to professionals of the public health system.


Objetivou-se neste estudo aplicar o Modelo de Crenças em Saúde a fim de explicar a adesão à recomendação de não reencapar agulhas por cirurgiões-dentistas e auxiliares de saúde bucal da rede pública de um município paulista. Utilizou-se um questionário validado e adaptado para a área de saúde bucal, que contemplava variáveis relativas à frequência do reencape e crenças em saúde, por meio de escalas tipo Likert. A relação entre as crenças e a adesão à recomendação de não reencapar agulhas foi obtida por meio da análise de regressão. Da amostra de profissionais obtida por adesão ao estudo (n = 79), a maioria (83,5%) relatou ter reencapado agulhas pelo menos alguma vez no último mês. Por meio da análise de regressão, foi observado que a relação entre as crenças descritas pelo modelo e a atitude de aderir ou não à recomendação de não reencapar agulhas foi explicada por uma menor percepção de barreiras psicológicas e por uma maior percepção de estímulos para não reencapar agulhas. Conclui-se que a aceitação das recomendações para prevenir acidentes do trabalho com material biológico foi explicado por algumas dimensões do Modelo de Crenças em Saúde, possibilitando a discussão sobre a reformulação de capacitações oferecidas para profissionais do sistema público de saúde.


Assuntos
Animais , Bovinos , Complexo I de Transporte de Elétrons/metabolismo , Células Endoteliais/enzimologia , Hiperóxia/metabolismo , Mitocôndrias/enzimologia , Artéria Pulmonar/citologia , Artéria Pulmonar/enzimologia , Ubiquinona/metabolismo , Aerobiose/efeitos dos fármacos , Benzoquinonas/farmacologia , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Cromatografia Líquida de Alta Pressão , Meios de Cultura , Complexo I de Transporte de Elétrons/antagonistas & inibidores , Células Endoteliais/efeitos dos fármacos , Inibidores Enzimáticos/farmacologia , Ferricianetos/farmacologia , L-Lactato Desidrogenase/metabolismo , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Oxirredução/efeitos dos fármacos , Consumo de Oxigênio/efeitos dos fármacos , Artéria Pulmonar/efeitos dos fármacos , Espectrofotometria , Cloreto de Tolônio/farmacologia , Ubiquinona/análise , Ubiquinona/farmacologia
10.
Braz. j. med. biol. res ; 46(7): 601-606, ago. 2013. graf
Artigo em Inglês | LILACS | ID: lil-682395

RESUMO

Interleukin (IL)-33, the most recent member of the IL family of cytokines, signals through the ST2 receptor. IL-33/ST2 signaling mediates antigen challenge-induced mechanical hyperalgesia in the joints and cutaneous tissues of immunized mice. The present study asked whether IL-33/ST2 signaling is relevant to overt pain-like behaviors in mice. Acetic acid and phenyl-p-benzoquinone induced significant writhing responses in wild-type (WT) mice; this overt nociceptive behavior was reduced in ST2-deficient mice. In an antigen-challenge model, ST2-deficient immunized mice had reduced induced flinch and licking overt pain-like behaviors. In the formalin test, ST2-deficient mice also presented reduced flinch and licking responses, compared with WT mice. Naive WT and ST2-deficient mice presented similar responses in the rota-rod, hot plate, and electronic von Frey tests, indicating no impairment of motor function or alteration in basal nociceptive responses. The results demonstrate that IL-33/ST2 signaling is important in the development of overt pain-like behaviors.


Assuntos
Animais , Camundongos , Hiperalgesia/metabolismo , Interleucinas/metabolismo , Dor Nociceptiva/fisiopatologia , Medição da Dor/métodos , Receptores de Interleucina/deficiência , Transdução de Sinais , Ácido Acético , Benzoquinonas , Homozigoto , Temperatura Alta , Camundongos Endogâmicos BALB C , Atividade Motora/fisiologia , Nociceptividade/fisiologia , Dor Nociceptiva/induzido quimicamente , Ovalbumina/imunologia , Teste de Desempenho do Rota-Rod
11.
Braz. j. med. biol. res ; 41(5): 403-410, May 2008. ilus
Artigo em Inglês | LILACS | ID: lil-484433

RESUMO

Intrahippocampal administration of kainic acid (KA) induces synaptic release of neurotrophins, mainly brain-derived neurotrophic factor, which contributes to the acute neuronal excitation produced by the toxin. Two protein tyrosine kinase inhibitors, herbimycin A and K252a, were administered intracerebroventricularly, in a single dose, to attenuate neurotrophin signaling during the acute effects of KA, and their role in epileptogenesis was evaluated in adult, male Wistar rats weighing 250-300 g. The latency for the first Racine stage V seizure was 90 ± 8 min in saline controls (N = 4) which increased to 369 ± 71 and 322 ± 63 min in animals receiving herbimycin A (1.74 nmol, N = 4) and K252a (10 pmol, N = 4), respectively. Behavioral alterations were accompanied by diminished duration of EEG paroxysms in herbimycin A- and K252a-treated animals. Notwithstanding the reduction in seizure severity, cell death (60-90 percent of cell loss in KA-treated animals) in limbic regions was unchanged by herbimycin A and K252a. However, aberrant mossy fiber sprouting was significantly reduced in the ipsilateral dorsal hippocampus of K252a-treated animals. In this model of temporal lobe epilepsy, both protein kinase inhibitors diminished the acute epileptic activity triggered by KA and the ensuing morphological alterations in the dentate gyrus without diminishing cell loss. Our current data indicating that K252a, but not herbimycin, has an influence over KA-induced mossy fiber sprouting further suggest that protein tyrosine kinase receptors are not the only factors which control this plasticity. Further experiments are necessary to elucidate the exact signaling systems associated with this K252a effect.


Assuntos
Animais , Masculino , Ratos , Benzoquinonas/farmacologia , Carbazóis/farmacologia , Epilepsia do Lobo Temporal/fisiopatologia , Alcaloides Indólicos/farmacologia , Ácido Caínico/antagonistas & inibidores , Lactamas Macrocíclicas/farmacologia , Fibras Musgosas Hipocampais/efeitos dos fármacos , Proteínas Tirosina Quinases/antagonistas & inibidores , Análise de Variância , Morte Celular/efeitos dos fármacos , Morte Celular/fisiologia , Eletroencefalografia , Inibidores Enzimáticos/farmacologia , Epilepsia do Lobo Temporal/induzido quimicamente , Epilepsia do Lobo Temporal/patologia , Agonistas de Aminoácidos Excitatórios/farmacologia , Ácido Caínico/farmacologia , Sistema Límbico/citologia , Sistema Límbico/efeitos dos fármacos , Fibras Musgosas Hipocampais/patologia , Fibras Musgosas Hipocampais/fisiopatologia , Fatores de Crescimento Neural , Ratos Wistar , Estatísticas não Paramétricas , Convulsões/fisiopatologia
12.
Ciênc. cult. (Säo Paulo) ; 48(1/2): 103-8, Jan.-Apr. 1996. ilus, tab
Artigo em Inglês | LILACS | ID: lil-191249

RESUMO

The toxicity of a polyhydroxy derivative of p-benzoquinone, tetrahydroxy-l,4-benzoquinone (THQ), was investigated in Chinese hamster ribroblasts (V79-M8 line). The fast oxidative degradation of THQ, yielding reactive oxygen species, allowed its use as a suitable tool to study the mechanisms of cell injury under oxidative stress. Toxicity of THQ to V79 cells was evaluated by measuring its inhibitory effects on cell growth and upon DNA synthesis rate. Complete prevention of both effects by catalase implicated hydrogen peroxide as the central key in the mechanism of THQ cytotoxicity. The roles of the primary oxidative product of THQ, rhodizonic acid (RDZ), as well as that of calcium, were investigated. The dependence of THQ on hydrogen peroxide for cytotoxicity, together with the possibility of iron chelation by RDZ, led us to propose an intracellular Fenton-type reaction as the mediator of THQ toxicity toward V79 cells. The understanding of THQ toxicity mechanisms can help to gain insights into the way structurally related physiological compounds, such as catechol derivatives, produce their toxic effects on target cells.


Assuntos
Animais , Cricetinae , Benzoquinonas/toxicidade , Espécies Reativas de Oxigênio , Estresse Oxidativo , Divisão Celular , DNA/biossíntese , Fibroblastos/citologia , Fibroblastos/efeitos dos fármacos , Radicais Livres , Peróxido de Hidrogênio , Inibidores da Síntese de Ácido Nucleico
13.
Braz. j. med. biol. res ; 25(6): 549-55, 1992. ilus
Artigo em Inglês | LILACS | ID: lil-109069

RESUMO

In the present study we have documented the use of the reagent p-benzoquinone (PBQ) for the spectrophotometric determination of total protein in blood plasma. Since the products of reaction are stable for several hours at room temperature after the 20-min boiling step, the time at which absorbance is measured is not a critical factor. Common anticoagulants such as EDTYA, citrate, or heparin do not interfere with the PBQ method at concentrations used in clinical laboratories. The products of the reaction between PBQ and either plasma (specific absorbance 2.33 x 10-3 ñ 0.20 x 10-3 ug cm -2) or purified proteins (specific absorbance 2.61 x 10-3 ñ 0.31 x 10-3 ug cm-2) show an absorption band at 350 nm, which follows Beer's law, and therefore can be used for analytical purposes. The PBQ method has a lower limit of detection (4 ug/ml) than that of biuret method (45 yg/ml) for a final reaction mixture of 5.0 and 4.2 ml, respectively


Assuntos
Anticoagulantes , Benzoquinonas , Proteínas/sangue , Espectrofotometria , Citratos , Ácido Edético , Heparina
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