Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 27
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Am J Chin Med ; 38(1): 37-49, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-20128043

RESUMO

Our previous studies have shown that daurisoline (DS) exerted antiarrhythmic effects on various experimental arrhythmias. In this study, the effects of DS on early afterdepolarizations (EADs) and its possible mechanisms have been investigated. Cardiac hypertrophy was induced in rabbits by coarctating the abdominal aorta. The effects of DS on action potential duration (APD) and the incidences of EADs were studied in hypertrophied papillary muscles of rabbits in the conditions of low external K(+) concentration ([K(+)]o) and dofetilide (dof) by using standard microelectrode technique. The whole-cell patch clamp was used to record the L-type calcium current (I(Ca-L)) in isolated left ventricular cells of rabbits. The results showed that in hypertrophied papillary muscles of rabbits with low [K(+)]o ([K(+)]o = 2.7 mM), 1 microM dof prolonged APD(50) and APD(90) markedly and the incidence of EADs was 66.7% (4/6, p < 0.01); when 15 microM DS was applied, the incidence of EADs was 0% (0/4, p < 0.01) and the prolonged APD was shortened (p < 0.01). In a single myocyte, DS could also inhibit EADs induced by dof, low [K(+)]o and low external Mg(2+) concentration ([Mg(2+)]o) ([Mg(2+)](o) = 0.5 mM). DS could decrease the triangulation. In a single myocyte, DS could make the I-V curve upward, shift the steady-state activation curves to the right and the steady-state inactivation curves to the left and prolong the tau value of recovery curve obviously. These results suggested that DS could inhibit EADs which may be associated with its blockade effects on I(Ca-L).


Assuntos
Potenciais de Ação/efeitos dos fármacos , Antiarrítmicos/farmacologia , Benzilisoquinolinas/farmacologia , Canais de Cálcio Tipo L/efeitos dos fármacos , Coração/efeitos dos fármacos , Menispermum/química , Extratos Vegetais/farmacologia , Animais , Antiarrítmicos/isolamento & purificação , Antiarrítmicos/uso terapêutico , Benzilisoquinolinas/isolamento & purificação , Benzilisoquinolinas/uso terapêutico , Sinalização do Cálcio/efeitos dos fármacos , Cardiomegalia/tratamento farmacológico , Modelos Animais de Doenças , Coração/fisiologia , Células Musculares/efeitos dos fármacos , Técnicas de Patch-Clamp , Fenetilaminas , Fitoterapia , Extratos Vegetais/química , Extratos Vegetais/uso terapêutico , Potássio/metabolismo , Coelhos , Rizoma , Sulfonamidas , Fatores de Tempo
2.
Can J Physiol Pharmacol ; 87(11): 954-62, 2009 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-19935903

RESUMO

We have previously reported that dauricine exerted antiarrhythmic effects on various experimental arrhythmias. To further clarify its mechanism, the effects of dauricine on action potential duration (APD), early afterdepolarizations (EADs), triangulation, which is defined as the repolarization time from APD at 30% level (APD30) to APD at 90% level (APD90), and L-type calcium current (I(Ca-L)) were studied using standard microelectrode techniques on rabbit papillary muscles and whole-cell patch clamp techniques on single myocytes isolated from rabbits by enzymatic digestion, respectively. Cardiac hypertrophy was induced by coarctating the abdominal aorta of rabbits. The results showed that in papillary muscles of hypertrophied rabbits, 1 micromol/L dofetilide, a selective IKr blocker, prolonged APD50 and APD90 and induced EADs (4/6, p < 0.01) with hypokalemia ([K+]o = 2.7 mmol/L). Dauricine inhibited EADs (p < 0.01) and shortened the prolonged APD (p < 0.01). In single myocytes, dauricine also inhibited EADs induced by dofetilide, hypokalemia, and hypomagnesaemia. Dauricine decreased the triangulation and reduced the peak amplitude of I(Ca-L) at all potentials tested. Dauricine shifted the steady-state activation curves to the right and steady-state inactivation curves to the left and prolonged the tau value of the recovery curve. These results suggest that dauricine inhibits EADs and this effect may be associated with its blockade of I(Ca-L).


Assuntos
Antiarrítmicos/farmacologia , Benzilisoquinolinas/farmacologia , Bloqueadores dos Canais de Cálcio/farmacologia , Canais de Cálcio Tipo L/metabolismo , Hipertrofia Ventricular Esquerda/fisiopatologia , Fármacos Neuromusculares Despolarizantes/farmacologia , Músculos Papilares/efeitos dos fármacos , Tetra-Hidroisoquinolinas/farmacologia , Potenciais de Ação/efeitos dos fármacos , Animais , Relação Dose-Resposta a Droga , Feminino , Técnicas In Vitro , Síndrome do QT Longo/induzido quimicamente , Magnésio/metabolismo , Masculino , Miócitos Cardíacos/efeitos dos fármacos , Técnicas de Patch-Clamp , Fenetilaminas/farmacologia , Potássio/metabolismo , Bloqueadores dos Canais de Potássio/farmacologia , Coelhos , Sulfonamidas/farmacologia
3.
Antimicrob Agents Chemother ; 53(12): 5055-9, 2009 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-19752279

RESUMO

Anti-Hantaan virus monoclonal antibody (AHM) is a murine monoclonal antibody against Hantaan virus being developed for the treatment of hemorrhagic fever with renal syndrome. The purpose of the present study was to describe the tolerance and pharmacokinetics of an intravenously administered single ascending dose of AHM in Chinese healthy volunteers. Four cohorts of 22 healthy subjects received AHM at 2.5 to 20 mg, and the results indicated that AHM was well tolerated. We established a highly sensitive, rapid, and accurate immunoassay for the kinetic analysis of AHM in serum. Serial blood samples were obtained after intravenous administration for up to 17 days. A one-compartment model was determined to best describe the disposition of AHM. The maximal level in serum and the area under the serum concentration-time curve were proportional to the doses. The mean clearance, the half-life, and the volume of distribution were constant, irrespective of the dose. AHM was slowly cleared and had a half-life of approximately 110 h. These data support the use of a treatment regimen in which AHM is given only once intravenously.


Assuntos
Anticorpos Monoclonais/farmacocinética , Antivirais/farmacocinética , Vírus Hantaan/imunologia , Animais , Anticorpos Monoclonais/administração & dosagem , Anticorpos Monoclonais/efeitos adversos , Anticorpos Monoclonais/imunologia , Antivirais/administração & dosagem , Antivirais/efeitos adversos , Antivirais/imunologia , Área Sob a Curva , Ensaio de Imunoadsorção Enzimática , Feminino , Meia-Vida , Humanos , Injeções Intravenosas , Masculino , Camundongos , Adulto Jovem
4.
Toxicol Lett ; 191(1): 1-8, 2009 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-19501137

RESUMO

The present study investigated the penetration and potential toxicity of titanium dioxide (TiO(2)) nanoparticles following its dermal exposure in vitro and in vivo. In vitro, after exposure to isolated porcine skin for 24h, titanium dioxide nanoparticles of carious sizes cannot penetrate through stratum corneum. Interestingly, when studied in vivo, quite different results were obtained. After topically applied on pig ear for 30 days, TiO(2) nanomaterials (4 nm and 60 nm) can penetrate through horny layer, and be located in deep layer of epidermis. Furthermore, after 60 days dermal exposure in hairless mice, nano-TiO(2) particles can penetrate through the skin, reach different tissues and induce diverse pathological lesions in several major organs. Notably, P25 (21 nm) TiO(2) nanomaterials shows a wider tissue distribution, and can even be found in the brain without inducing any pathological changes. Among all of the organs examined, the skin and liver displayed the most severe pathological changes that correspond to the significant changes in SOD and MDA levels. These results suggest that the pathological lesions are likely to be mediated through the oxidative stress induced by the deposited nanoparticles. Accordingly, the collagen content expressed as HYP content are also significantly reduced in mouse skin samples, indicating that topically applied nano-TiO(2) in skin for a prolonged time can induce skin aging. Altogether, the present study indicates that nanosize TiO(2) may pose a health risk to human after dermal exposure over a relative long time period.


Assuntos
Materiais Biocompatíveis/farmacocinética , Materiais Biocompatíveis/toxicidade , Absorção Cutânea/fisiologia , Titânio/farmacocinética , Titânio/toxicidade , Animais , Peso Corporal/fisiologia , Cultura em Câmaras de Difusão , Orelha Externa/metabolismo , Humanos , Hidroxiprolina/metabolismo , Técnicas In Vitro , Irritantes/toxicidade , Masculino , Malondialdeído/metabolismo , Camundongos , Camundongos Pelados , Camundongos Endogâmicos BALB C , Microscopia Eletrônica de Transmissão , Tamanho da Partícula , Pele/patologia , Espectrofotometria Atômica , Superóxido Dismutase/metabolismo , Suínos , Distribuição Tecidual
5.
Planta Med ; 75(2): 121-6, 2009 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-19031363

RESUMO

Scutellarin (Scu) is the major active principle (flavonoid) extracted from Erigeron breviscapus (Vant.) Hand-Mazz, a Chinese herbal medicine. In this paper, we investigated the effects of Scu on brain injury through the inhibition of AIF-mediated apoptosis induced by transient focal brain ischemia in rats. Rats were treated with Scu for 7 d and then subjected to cerebral ischemia/reperfusion (I/R) injury induced by a middle cerebral artery occlusion (MCAO). After 2 h of ischemia and 22 h of reperfusion, the infarct volume and the neurological deficit were determined by TTC staining and Longa's score. IN SITU end-labeling of nuclear DNA fragments (TUNEL) was employed to determine the degree of DNA fragmentation. NAD content and PARP activity in brain homogenate were determined. The expression of AIF in the nucleus was analyzed by Western blot. The present study showed that Scu significantly reduced the infarct volume and ameliorated the neurological deficit. An increase in the number of TUNEL-positive cells and a decrease in the NAD level were also observed after 2 h of ischemia and 22 h of reperfusion. At the same time, Scu (50 and 75 mg kg (-1), i. g.) treatment reversed brain NAD depletion and reduced DNA fragmentation. Scu also inhibited PARP overactivation and AIF translocation from the mitochondria to the nucleus following cerebral I/R. These findings suggested that the neuroprotective effects of Scu on brain ischemic injury-induced apoptosis might be associated with inhibition of PARP-dependent mitochondrial dysfunction and subsequent translocation of AIF.


Assuntos
Apigenina/uso terapêutico , Fator de Indução de Apoptose/metabolismo , Isquemia Encefálica/tratamento farmacológico , Erigeron , Glucuronatos/uso terapêutico , Mitocôndrias/efeitos dos fármacos , Fármacos Neuroprotetores/uso terapêutico , Extratos Vegetais/uso terapêutico , Animais , Apigenina/farmacologia , Apoptose/efeitos dos fármacos , Fator de Indução de Apoptose/genética , Transporte Biológico , Encéfalo/efeitos dos fármacos , Núcleo Celular/metabolismo , Fragmentação do DNA/efeitos dos fármacos , Glucuronatos/farmacologia , Infarto da Artéria Cerebral Média/tratamento farmacológico , Masculino , Mitocôndrias/metabolismo , NAD/metabolismo , Fármacos Neuroprotetores/farmacologia , Fitoterapia , Extratos Vegetais/farmacologia , Poli(ADP-Ribose) Polimerases/metabolismo , Ratos , Ratos Sprague-Dawley
6.
Cell Mol Neurobiol ; 28(4): 613-27, 2008 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-17710536

RESUMO

Piracetam is the derivate of gamma-aminobutyric acid, which improves the cognition,memory,consciousness, and is widely applied in the clinical treatment of brain dysfunction. In the present experiments, we study the effects of piracetam on chronic cerebral hypoperfused rats and observe its influence on amino acids, synaptic plasticity in the Perforant path-CA3 pathway and apoptosis in vivo. Cerebral hypoperfusion for 30 days by occlusion of bilateral common carotid arteries induced marked amnesic effects along with neuron damage, including: (1) spatial learning and memory deficits shown by longer escape latency and shorter time spent in the target quadrant; (2) significant neuronal loss and nuclei condensation in the cortex and hippocampus especially in CA1 region; (3) lower induction rate of long term potentiation, overexpression of BAX and P53 protein, and lower content of excitatory and inhibitory amino acids in hippocampus. Oral administration of piracetam (600 mg/kg, once per day for 30 days) markedly improved the memory impairment, increased the amino acid content in hippocampus, and attenuated neuronal damage. The ability of piracetam to attenuate memory deficits and neuronal damage after hypoperfusion may be beneficial in cerebrovascular type dementia.


Assuntos
Transtornos Cognitivos/tratamento farmacológico , Transtornos Cognitivos/etiologia , Hipóxia-Isquemia Encefálica/complicações , Piracetam/uso terapêutico , Animais , Avaliação Pré-Clínica de Medicamentos , Eletrofisiologia , Masculino , Aprendizagem em Labirinto/efeitos dos fármacos , Fármacos Neuroprotetores/uso terapêutico , Ratos , Ratos Sprague-Dawley , Natação , Proteína Supressora de Tumor p53/metabolismo , Proteína X Associada a bcl-2/metabolismo
7.
Yao Xue Xue Bao ; 42(1): 66-70, 2007 Jan.
Artigo em Chinês | MEDLINE | ID: mdl-17520810

RESUMO

To observe the pharmacokinetic and tissue-distribution characters of 5-flourouracil magnetic albumin deuto-microsphere (5-Fu-MAD) in normal and tumor-bearing mice, HPLC method for the determination of 5-Fu in plasma and tissues was established and applied to determine 5-Fu in mouse plasma and tissue samples. A Flame atomic absorption spectrometer was used to detect the iron concentration in mouse tissue. Plasma concentration-time curves of free 5-Fu, 5-Fu-MAD and 5-Fu-MAD plus the magnetic frame (MF) conformed to two compartment model of first order absorption and they had C(max) of 34.9, 7.95 and 5.97 mg x L(-1); T1/2 (Ke) of 22.26, 76.0 and 124.6 min, V(d) of 3.28, 30.7 and 66.1 L x kg; AUC(0-t), of 233.9, 78.3 and 50.2 mg x min x L(-1); AUC(0-infinity) of 237.2, 89.3 and 68.1 mg x min x L(-1), respectively. The distribution of 5-Fu and iron was the highest in the plenty blood perfusion organs like the liver, tumor, spleen and lung, while lower in the kidney and heart and lowest in brain and muscle. The tissue distribution of muscle and tumor increased significantly when a magnetic frame was inserted there. The pharmacokinetics and tissue distribution of 5-Fu-MAD exhibited sustained-release and target characteristics.


Assuntos
Antimetabólitos Antineoplásicos/farmacocinética , Fluoruracila/farmacocinética , Neoplasias Hepáticas Experimentais/prevenção & controle , Microesferas , Albuminas/química , Animais , Antimetabólitos Antineoplásicos/administração & dosagem , Área Sob a Curva , Linhagem Celular Tumoral , Preparações de Ação Retardada , Feminino , Fluoruracila/administração & dosagem , Fígado/metabolismo , Fígado/patologia , Neoplasias Hepáticas Experimentais/metabolismo , Neoplasias Hepáticas Experimentais/patologia , Magnetismo , Masculino , Camundongos , Distribuição Aleatória , Distribuição Tecidual
8.
Zhongguo Zhong Yao Za Zhi ; 30(17): 1361-3, 2005 Sep.
Artigo em Chinês | MEDLINE | ID: mdl-16323549

RESUMO

OBJECTIVE: To discuss the anti-inflammatory mechanism of sinomenine on inflammatory media in joint of adjuvant arthritis rats. METHOD: Rats were randomly divided into the normal group and the model group, the prednisone group, the small, medium, large of sinomenine group (30, 60, 120 mg x kg(-1)). Except for the rats in the normal group, animals were modeled to adjuvant arthritiswith freund's complete adjuvant. The arthritis index (AI) and the swelling degree of paws were recorded, and the activity of IL-1, TNF and the levels of NO, PGE2 in joint fluids of secondary arthritis were determined. RESULT: Compared with the normal group, the activity of IL-1, TNF and the levels of NO, PGE2 in joint fluids of secondary arthritis were increased significantly in the model group (P < 0.05). Compared with the model group, it was shown to exert a dramatic inhibitory effect on secondary reaction of freund's adjuvant arthritis of rats, and the activity of IL-1, TNF and the levels of NO, PGE2 in joint fluids of secondary arthritis were significantly decreased in the sinomenine group (P < 0.05). CONCLUSION: Sinomenine has a remarkable treatment effect on RA. It is via NO to inhibit the activity of cytokines and decrease the level of inflammation mediators, which may be one of its curing RA mechanism.


Assuntos
Artrite Experimental/tratamento farmacológico , Morfinanos/uso terapêutico , Óxido Nítrico/metabolismo , Fitoterapia , Líquido Sinovial/metabolismo , Animais , Anti-Inflamatórios não Esteroides/uso terapêutico , Dinoprostona/metabolismo , Medicamentos de Ervas Chinesas/uso terapêutico , Interleucina-1/metabolismo , Masculino , Distribuição Aleatória , Ratos , Ratos Wistar , Sinomenium/química
9.
Am J Chin Med ; 33(6): 923-34, 2005.
Artigo em Inglês | MEDLINE | ID: mdl-16355449

RESUMO

Gap junction communication between astrocytes plays an important role in the brain. The purpose of this study was to investigate the effects of Gingko biloba extract (GBE) on the changes of connexin 43 (Cx43) mRNA and protein expression levels of rat cortex and hippocampus induced by ischemia-reperfusion and astrocyte gap junction intercellular communication (GJIC) induced by hypoxia-reoxygenation. After 2 hours of middle cerebral artery occlusion (MCAO) followed by 24 hours of reperfusion, there was obvious neurological deficit in rats. Cx43 mRNA and protein expression levels of rat cortex and hippocampus in the ischemia hemisphere were decreased significantly. When GBE at doses of 50 and 100 mg/kg body weight was administrated by p.o. daily for 7 days, the neurological deficit was improved, and lower Cx43 mRNA and protein expression levels induced by ischemia-reperfusion were recovered to normal. The i.p. injection of nimodipine (0.7 mg/kg weight body) also showed improvement on neurological deficit and Cx43 expression levels. Astrocyte GJIC was measured by the fluorescence recovery after photobleaching (FRAP). Hypoxia-reoxygenation induced a significant decrease in GJIC. Pretreatment with GBE (100 mg/l) and nimodipine (1.6 mg/l) significantly prevented the hypoxia-reoxygenation inhibition of GJIC. These results suggest that GBE could exert its neuroprotective effects by improvement of Cx43 expression and GJIC induced by hypoxia/ischemia-reoxygenation/ reperfusion injury.


Assuntos
Isquemia Encefálica/tratamento farmacológico , Junções Comunicantes/efeitos dos fármacos , Ginkgo biloba , Extratos Vegetais/farmacologia , Traumatismo por Reperfusão/tratamento farmacológico , Animais , Astrócitos/efeitos dos fármacos , Comunicação Celular/efeitos dos fármacos , Células Cultivadas , Conexina 43/metabolismo , Injeções Intraperitoneais , Masculino , Nimodipina/farmacologia , RNA Mensageiro/metabolismo , Ratos , Ratos Sprague-Dawley , Vasodilatadores/farmacologia
10.
Acta Pharmacol Sin ; 26(12): 1454-9, 2005 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-16297343

RESUMO

AIM: To investigate the neuroprotective effect and mechanisms of scutellarin, a flavonoid extracted from Erigeron breviscapus Hand Mazz, against neuronal damage following cerebral ischemia/reperfusion. METHODS: Rats were pretreated ig with scutellarin for 7 d and then subjected to cerebral ischemia/reperfusion (I/R) injury induced by a middle cerebral artery occlusion (MCAO). The infarct volume and neurological deficit were determined by TTC staining and Longa's score. The permeability of the blood-brain barrier was evaluated by measurement of the Evans blue (EB) content in the brain with a spectrophotometer. The total NOx content was determined. Nitric oxide synthase (NOS) isoforms (iNOS, eNOS, nNOS) and the key angiogenic molecules, vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF), were detected by Western blotting. RESULTS: Scutellarin significantly reduced infarct volume (P<0.05 or P<0.01), ameliorated the neurological deficit and reduced the permeability of the blood-brain barrier (BBB) (P<0.05). When rats were pretreated with scutellarin (50 or 75 mg/kg), upregulation of eNOS expression and downregulation of VEGF, bFGF, and iNOS expression was observed, whereas scutellarin had no effect on nNOS expression. CONCLUSION: Scutellarin has protective effects for cerebral injury through regulating the expression of NOS isoforms and angiogenic molecules.


Assuntos
Apigenina/farmacologia , Encéfalo/patologia , Glucuronatos/farmacologia , Fármacos Neuroprotetores/farmacologia , Traumatismo por Reperfusão/patologia , Animais , Apigenina/isolamento & purificação , Barreira Hematoencefálica/efeitos dos fármacos , Encéfalo/metabolismo , Isquemia Encefálica/complicações , Erigeron/química , Fator 2 de Crescimento de Fibroblastos/metabolismo , Glucuronatos/isolamento & purificação , Infarto da Artéria Cerebral Média/complicações , Masculino , Fármacos Neuroprotetores/isolamento & purificação , Óxido Nítrico Sintase Tipo I/metabolismo , Óxido Nítrico Sintase Tipo II/metabolismo , Óxido Nítrico Sintase Tipo III/metabolismo , Plantas Medicinais/química , Ratos , Ratos Sprague-Dawley , Traumatismo por Reperfusão/metabolismo , Fator A de Crescimento do Endotélio Vascular/metabolismo
11.
Zhongguo Zhong Yao Za Zhi ; 30(13): 1009-13, 2005 Jul.
Artigo em Chinês | MEDLINE | ID: mdl-16161431

RESUMO

OBJECTIVE: To observe the effects of ginkgolides on gene expression of hepatic cytochrome P-450 in rats. METHOD: Sprague-Dawley rats were administered ginkgolides (100 mg x kg(-1) body weight) through oral gavage once daily for four consecutive days. The level of gene expression in liver tissues was analyzed by competitive reverse transcription-polymerase chain reaction (competitive RT-PCR). RESULT: A single and prospective band of CYP1A1, CYP1A2, CYP2B1/B2, CYP2C11, CYP2E1, CYP4A1 and cyclophilin was observed after polymerase chain reaction (PCR) when the reactive system of reverse transcription (RT) had no target RNA, which confirmed the competitor had a specific capacity to bind to the CYP or cyclophilin primer. CYP1A1 mRNA was not dectectable in the livers of untreated control rats and ginkgolides-treated rats. The levels of CYP2C11 and CYP2E1 were not changed by ginkgolides treatment. In contrast, the levels of gene expression for CYP1A2 and CYP2B1/B2 were decreased, however, the levels of gene expression for CYP3A1 and CYP4A1 in ginkgolides group were distinctly increased compared with the control. CONCLUSION: A specific effect of ginkgolides on cytochrome P-450 gene expression was observed in this investigation. Ginkgolides had various effects on different cytochrome P-450 isoforms.


Assuntos
Citocromo P-450 CYP1A1/biossíntese , Sistema Enzimático do Citocromo P-450/biossíntese , Ginkgolídeos/farmacologia , Fígado/metabolismo , Animais , Hidrocarboneto de Aril Hidroxilases/biossíntese , Hidrocarboneto de Aril Hidroxilases/genética , Citocromo P-450 CYP1A1/genética , Citocromo P-450 CYP1A2/biossíntese , Citocromo P-450 CYP1A2/genética , Citocromo P-450 CYP2B1/biossíntese , Citocromo P-450 CYP2B1/genética , Citocromo P-450 CYP3A , Sistema Enzimático do Citocromo P-450/genética , Família 4 do Citocromo P450 , Regulação da Expressão Gênica , Ginkgo biloba/química , Ginkgolídeos/isolamento & purificação , Masculino , Plantas Medicinais/química , RNA Mensageiro/biossíntese , RNA Mensageiro/genética , Distribuição Aleatória , Ratos , Ratos Sprague-Dawley
12.
Yao Xue Xue Bao ; 40(3): 213-9, 2005 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-15952591

RESUMO

AIM: To investigate glutamate-induced [Ca2+]i changes in cultured rat neonatal cortical astrocytes after hypoxia/reoxygenation, H2O2 or high concentration of L-glutamate injury. In the meantime, the effects of Gingko biloba extract (GbE) were examined. METHODS: [Ca2+]i changes in astrocytes were monitored by laser scanning confocal microscopy with the Ca2+ sensitive fluorescent probe fluo-3. RESULTS: After astrocytes were impaired by hypoxia/reoxygenation, H2O2 (50 micromol x L(-1)) or L-glutamate (0.25 mmol x L(-)), the exogenous glutamate (27 micromol x L(-1)) could not induce increase of [Ca2+]i, but decrease by (3.3 +/- 1.6)%, (81 +/- 11)% and (81 +/- 7)%, respectively. Pretreatment with GbE (10 mg x L(-1)) could not improve injured astrocytic glutamate response. But after pretreatment with GbE (100 mg x L(-1)), glutamate-induced [Ca2+]i elevation of astrocytes after hypoxia/reoxygenation, H2O2 or high concentration of L-glutamate injury were (135 +/- 98)%, (117 +/- 93)% and (89 +/- 36)%, respectively. Nimodipine (1.6 mg x L(-1)) could also reverse the abnormal response of astrocytes after different injury. CONCLUSION: Hypoxia/reoxygenation, H2O2 and high concentration of L-glutamate impaired astrocytes' response to exogenous L-glutamate, and then bidirectional communication between astrocytes and neurons could not take place. GbE could improve the abnormal responses and maintain the normal function of astroglical network. These effects support that GbE has potential beneficial actions against brain injury.


Assuntos
Astrócitos/metabolismo , Cálcio/metabolismo , Medicamentos de Ervas Chinesas/farmacologia , Ginkgo biloba , Animais , Astrócitos/citologia , Hipóxia Celular , Células Cultivadas , Córtex Cerebral/citologia , Córtex Cerebral/metabolismo , Medicamentos de Ervas Chinesas/isolamento & purificação , Ginkgo biloba/química , Ácido Glutâmico/toxicidade , Peróxido de Hidrogênio/toxicidade , Folhas de Planta/química , Plantas Medicinais/química , Ratos , Traumatismo por Reperfusão
13.
Yao Xue Xue Bao ; 39(6): 401-5, 2004 Jun.
Artigo em Chinês | MEDLINE | ID: mdl-15491093

RESUMO

AIM: To study the protective effect of procyanidins from the seedpod of the lotus (LSPC) on myocardial ischemia and reperfusion in rats. METHODS: Myocardial injury model was made by ligating the coronary artery for 30 min followed by reperfusion for 45 min in anesthetized rat and 30 min of ischemia followed by 30 min of reperfusion in the isolated rat heart. All animals were given the medicine or normal saline before the experiment. ET, Ang I, Ang II in the serum, the MDA content, SOD activity, NO level, the recovery rate of coronary flow (CF) and heart rate (HR) after reperfusion and CK, XO from the myocardial cells were observed. RESULTS: LSPC was shown to inhibit the release of ET, Ang II (P < 0.05) , and the increase of MDA content (P < 0.05). It was also found to increase the SOD activity (P < 0.05) and NO level (P < 0.01). LSPC was found to increase the recovery rate of the coronary flow (CF) and heart rate (HR) after reperfusion (P < 0.05 or P < 0.01), decrease the release of CK from the myocardial cells (P < 0.01), depress the XO activity of myocardial tissue (P < 0.05), as well as improve the myocyte ultrastructural pathological injury. CONCLUSION: The anti-ischemia effect of LSPC was related to the mechanism of scavenging the oxygen free radicals directly, cutting off the source of free radicals, reducing tissue peroxidation, stabilizing the cells membrane, depressing the production of EDCF and increasing the NO level as well.


Assuntos
Biflavonoides/farmacologia , Cardiotônicos/farmacologia , Catequina/farmacologia , Lotus/química , Isquemia Miocárdica/tratamento farmacológico , Traumatismo por Reperfusão Miocárdica , Traumatismo por Reperfusão Miocárdica/tratamento farmacológico , Proantocianidinas/farmacologia , Animais , Biflavonoides/isolamento & purificação , Catequina/isolamento & purificação , Circulação Coronária/efeitos dos fármacos , Masculino , Isquemia Miocárdica/metabolismo , Traumatismo por Reperfusão Miocárdica/metabolismo , Miocárdio/enzimologia , Miocárdio/ultraestrutura , Proantocianidinas/isolamento & purificação , Ratos , Ratos Wistar
14.
Yao Xue Xue Bao ; 39(6): 419-23, 2004 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-15491097

RESUMO

AIM: To investigate the protective effects of sodium beta-aescin on cerebral ischemia-reperfusion injury in rats. METHODS: Rats were pretreated with sodium beta-aesein for 7 d and then subjected to cerebral ischemia-reperfusion injury induced by a middle cerebral artery occlusion (MCAO). The neurological outcome was evaluated by the Longa's method; The infarct volume was assessed by hemmatoxylin-Eosin staining and the cerebral water content was measured by dry weight method. The activities of SOD, GSH-Px, CAT, Na+ -K+ -ATPase and the MDA content were measured in the cortex and hippocampus of ischemic and non-ischemic hemisphere. RESULTS: Sodium beta-aescin significantly reduced the volume of cerebral infarct and water content, and ameliorated the neurological deficit (P < 0.05). In vehicle-treated rats, the activities of SOD, GSH-Px and Na+ -K+ -ATPase in the cortex and hippocampus of ischemic hemisphere were all decreased (P < 0.01) , while the CAT activity was slightly elevated and the MDA of content was significantly increased (P < 0.01) compared with the sham-operated group. After treated with sodium beta-aescin, the effects on recovery of SOD, GSH-Px, Na+ -K+ -ATPase activities were observed (P < 0.05), and the MDA content was reduced (P < 0.05). CONCLUSION: These results showed that pretreatment with sodium beta-aescin can attenuate brain injury and its antioxidant activity on rats which encountered cerebral ischemia-reperfusion.


Assuntos
Isquemia Encefálica/metabolismo , Encéfalo/metabolismo , Escina/farmacologia , Fármacos Neuroprotetores/farmacologia , Traumatismo por Reperfusão/metabolismo , Animais , Isquemia Encefálica/patologia , Catalase/metabolismo , Glutationa Peroxidase/metabolismo , Masculino , Malondialdeído/metabolismo , Ratos , Ratos Sprague-Dawley , Traumatismo por Reperfusão/patologia , ATPase Trocadora de Sódio-Potássio/metabolismo , Superóxido Dismutase/metabolismo
15.
Acta Pharmacol Sin ; 25(10): 1267-75, 2004 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-15456527

RESUMO

AIM: To investigate the effects of beta-aescin on apoptosis induced by transient focal brain ischemia in rats. METHODS: Rats were pretreated with beta-aescin for 7 d and then subjected to brain ischemia/reperfusion (I/R) injury induced by a middle cerebral artery occlusion. After 2 h ischemia and 24 h reperfusion, Hematoxylin-Eosin (HE) staining, in situ end-labeling of nuclear DNA fragmentation (TUNEL) were employed to determine the level of apoptosis. The expressions of caspase-3 and Bcl-2 in the cortex were determined by immunohistochemistry and Western blot. The release of cytochrome c was analyzed by Western blot. RESULTS: The increased numbers of HE- and TUNEL-positive staining cells were significantly observed at 24 h after reperfusion. The immunoreactivity was inhibited by beta-aescin (30, 60 mg/kg) (P<0.01 or P<0.05 vs vehicle-treated). After cerebral I/R, cytochrome c was released into the cytosol and caspase-3 was activated, whereas Bcl-2 expression was inhibited. beta-Aescin (30, 60 mg/kg) markedly inhibited the expression of caspase-3 and the release of cytochrome c, and up-regulated the expression of Bcl-2 (P<0.05, P<0.01 vs vehicle-treated). CONCLUSION: beta-Aescin could potently inhibit caspase-3 activation and the release of cytochrome c, increasing the expression of Bcl-2 after cerebral I/R in rats. These findings on the inhibitory effects of beta-aescin on brain ischemic injury-induced apoptosis might have important theoretical basis for the treatment on ischemic cerebrovascular diseases.


Assuntos
Apoptose/efeitos dos fármacos , Escina/farmacologia , Traumatismo por Reperfusão/patologia , Animais , Isquemia Encefálica/etiologia , Caspase 3 , Caspases/metabolismo , Córtex Cerebral/enzimologia , Córtex Cerebral/metabolismo , Citocromos c/metabolismo , Infarto da Artéria Cerebral Média/complicações , Masculino , Mitocôndrias/enzimologia , Fármacos Neuroprotetores/farmacologia , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Ratos , Ratos Sprague-Dawley , Traumatismo por Reperfusão/etiologia , Traumatismo por Reperfusão/metabolismo
16.
Zhonghua Liu Xing Bing Xue Za Zhi ; 25(5): 435-8, 2004 May.
Artigo em Chinês | MEDLINE | ID: mdl-15231175

RESUMO

OBJECTIVE: To assess the current status on re-evaluation of marketed drug in China since the promulgation of drug law in 1985. METHODS: Review of literature on Chinese pharmaceutical abstract and CBMdisc from 1985 to 2001 year was done. RESULTS: 4029 papers and 855 marketed drugs from 1985 to 2001 were included. Drugs on anti-infection agent, cardiovascular system and digestive system were the main drugs being re-evaluated, with the proportions of 27.1%, 20.1% and 11.1% respectively. The amounts of both marketed drugs and literature were increasing year by year. The method used for re-evaluation were random and non-random clinical trial. 41.4% of all the samples had a sample size of 50 - 100 research subjects. There were 13 papers with more than 5000 samples. The level on evidence based literature was assessed. 44 papers were graded as first class, and 182 papers the second, 2466 papers the third and 1337 papers the fourth. The quality of literature was improved year by year. CONCLUSION: The amount, quality as well as the sample size of literature being re-evaluated on marketed drug were increased from 1985 to 2001. However, the design and evaluation of those trials were not standardized.


Assuntos
Anti-Infecciosos/uso terapêutico , Produtos Biológicos/uso terapêutico , Fármacos Cardiovasculares/uso terapêutico , Vigilância de Produtos Comercializados , China , Ensaios Clínicos como Assunto , Análise Custo-Benefício , Medicina Baseada em Evidências , Humanos
17.
Acta Pharmacol Sin ; 25(7): 869-75, 2004 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-15210059

RESUMO

AIM: To investigate the effects of sodium beta-aescin on neutrophil migration and expression of adhesion molecules (ICAM-1 and E-selectin) after middle cerebral artery occlusion (MCAO) in rats. METHODS: Rats were pretreated with sodium beta-aescin for 7 d and then subjected to cerebral ischemia/reperfusion (I/R) injury induced by an MCAO. After a 2-h ischemia and a 24-h reperfusion, the infarct volume and neurological deficit were determined by the method of TTC staining and the Longa's score. The effect of sodium beta-aescin on the migration of neutrophils was evaluated by measuring the activity of myeloperoxidase (MPO) enzyme. The expressions of adhesion molecules were determined by immunohistochemistry and Western blot. RESULTS: Sodium beta-aescin significantly reduced the cerebral infarct volume and ameliorated the neurological deficit (P<0.05 or P<0.01). The MPO activity and the expressions of ICAM-1 and E-selectin in the vehicle-treated rats were increased significantly (P<0.01) after cerebral I/R. After treatment with sodium beta-aescin, the enzymatic activity of MPO and the expressions of these adhesion molecules were significantly reduced compared with the vehicle-treated group (P<0.05 or P<0.01). CONCLUSION: Sodium beta-aescin can attenuate brain injury, down-regulate the protein expressions of ICAM-1 and E-selectin, and reduce the migration of neutrophils after cerebral I/R.


Assuntos
Selectina E/metabolismo , Escina/farmacologia , Infarto da Artéria Cerebral Média/metabolismo , Molécula 1 de Adesão Intercelular/metabolismo , Neutrófilos/fisiologia , Aesculus/química , Animais , Movimento Celular/efeitos dos fármacos , Infarto Cerebral/complicações , Regulação para Baixo , Escina/isolamento & purificação , Infarto da Artéria Cerebral Média/patologia , Masculino , Fármacos Neuroprotetores/farmacologia , Peroxidase/metabolismo , Plantas Medicinais/química , Ratos , Ratos Sprague-Dawley , Traumatismo por Reperfusão/etiologia , Traumatismo por Reperfusão/metabolismo
18.
Chin Med J (Engl) ; 117(6): 856-61, 2004 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-15198887

RESUMO

BACKGROUND: A voluntary procedure for reporting adverse drug reactions (ADRs) was formally put in place in 1989. However, only a small proportion of ADR reports are actually forwarded to the national monitoring center. To identify the reasons for underreporting, the authors investigated the awareness and attitudes of healthcare professionals (doctors, nurses, and administrators) toward the ADR system in China. In addition, the authors sought to formulate approaches to improve the current ADR reporting system. METHODS: Structured interviews were carried out in 16 hospitals selected from 27 municipal hospitals in Wuhan, Hubei Province, China. A questionnaire survey of a stratified random sample of approximately 15% of healthcare professionals in each selected hospital was conducted during February to March 2003. RESULTS: The response rate of this survey was 85%. One thousand six hundred and fifty-three questionnaires were used in the final analysis. Only 2.7% of the healthcare professionals had a correct understanding to the definition of ADR. Eighty-nine point two percent of the healthcare professionals had encountered ADRs. Ninety-four percent of them were aware of the need to report these to the ADR monitoring center. However, only 28.5% of doctors, 22.8% of nurses, and 29.7% of administrators actually submitted a report. For the most part, they reported ADRs to the hospital pharmacy (66.0%), to other departments in the hospital (72.5%), and to the pharmaceutical industry (23.0%), rather than to the national monitoring center (2.9%) or regional monitoring center (9.5%). Severe or rare ADRs and ADRs to new products were generally perceived to be significant enough to report. Sixty-two point one percent of the healthcare professionals had encountered ADRs, yet not reported them to anybody. The major reasons for not reporting included no knowledge of the reporting procedure (71.4%), unavailability of the reporting center mailing address (67.9%), unavailability of the ADR report form (60.4%), lack of knowledge of the existence of a national ADR reporting system (52.2%), and belief that the ADR in question was already well known (44.1%). CONCLUSIONS: Healthcare professionals in Wuhan, China have little basic knowledge of ADR and of the voluntary reporting system. The main reasons for underreporting were lack of basic knowledge about ADRs and the voluntary reporting procedure. Education and training of healthcare professionals is needed to improve the current ADR reporting system.


Assuntos
Sistemas de Notificação de Reações Adversas a Medicamentos/tendências , Atitude do Pessoal de Saúde , China , Conhecimentos, Atitudes e Prática em Saúde , Administradores Hospitalares , Humanos , Entrevistas como Assunto , Enfermeiras e Enfermeiros , Médicos , Inquéritos e Questionários
19.
Zhonghua Liu Xing Bing Xue Za Zhi ; 25(10): 894-7, 2004 Oct.
Artigo em Chinês | MEDLINE | ID: mdl-15631751

RESUMO

OBJECTIVE: To investigate the knowledge and attitudes of healthcare professionals (doctors, nurses and administrators) to adverse drug reactions (ADR) in Wuhan city and to identify the reasons for under-reporting. METHODS: Structured interviews were carried out in Wuhan, Hubei province. Questionnaire survey to approximately 15% of the medical practitioners selected from 16 hospitals, was conducted during the period from February to March 2003. RESULTS: Only 2.7% of the interviewees knew the definition of adverse drug reactions. 61.7% of the doctors, 62.7% of the nurses and 61.1% of the administrators had ever encountered an ADR during their practices, but did not report to the national monitoring center or other centers. The major reasons for not reporting included: ignorant about the requirement and the reporting process of ADR (71.4%); address of the reporting agency and Forms unavailable (67.9%, 60.4%); unaware of the existence of a national ADR reporting system (52.2%); needless to report as the ADR being too well known (44.1%). They mainly reported an ADR to the hospital pharmacy or other departments, or to the pharmaceutical administration. Education, training and developing new institutions were ways to improve the reporting system. CONCLUSIONS: Our results showed that healthcare professionals had little knowledge on the basic ADR knowledge. The main reasons for underreporting were related to factors on reporting process, address of related centers and unavailable of the Forms. Education and training to doctors and nurses to enhance the awareness of administrators were the ways to improve the reporting system.


Assuntos
Atitude do Pessoal de Saúde , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos , Conhecimentos, Atitudes e Prática em Saúde , Sistemas de Notificação de Reações Adversas a Medicamentos , China , Feminino , Humanos , Masculino , Padrões de Prática Médica , Inquéritos e Questionários
20.
Acta Pharmacol Sin ; 24(11): 1118-24, 2003 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-14627496

RESUMO

AIM: To investigate the effects of scutellarin (Scu) on liver function after brain ischemia/reperfusion in Wistar rats. METHODS: Rats were pretreated with Scu for 7 d and then subjected to a brain ischemia/reperfusion injury induced by a middle cerebral artery occlusion. The levels of nitric oxide (NO), xanthine oxidase (XOD), alanine transaminase (ALT), and aspartate aminotransferase (AST) in serum or liver tissues and the activities of antioxidant enzymes and cytochrome P450-dependent monooxygenases (CYPs) in liver tissues after brain ischemia/reperfusion were determined. RESULTS: In vehicle-treated rats, XOD, ALT, and AST activities (P<0.01) in serum and the MDA level (P<0.05) in liver tissues were all elevated but were significantly reduced (P<0.05) by Scu pretreatment. The NO levels in serum and liver tissues were decreased (P<0.01) dramatically in vehicle-treated rats and returned to the levels in the sham-operated animals when pretreated with Scu. SOD (P<0.05) and GSH-PX (P<0.01) activities in cytosol fraction were increased significantly by Scu pretreatment. Furthermore, a loss of CYP3A activity (P<0.01), but no changes of CYP1A1, CYP1A2, and CYP2E1 activities in liver were observed after brain ischemia/reperfusion in rats. Scu had no effect on them. CONCLUSION: These results demonstrated that pretreatment with Scu could attenuate hepatocellular damage elicited by brain ischemia/reperfusion in rats and this protection is in major part by its antioxidant activity.


Assuntos
Antioxidantes/farmacologia , Fígado/metabolismo , Traumatismo por Reperfusão/metabolismo , Alanina Transaminase/sangue , Animais , Hidrocarboneto de Aril Hidroxilases/metabolismo , Aspartato Aminotransferases/sangue , Isquemia Encefálica/complicações , Citocromo P-450 CYP3A , Glutationa Peroxidase/metabolismo , Masculino , Malondialdeído/metabolismo , Óxido Nítrico/sangue , Óxido Nítrico/metabolismo , Oxirredutases N-Desmetilantes/metabolismo , Ratos , Ratos Wistar , Traumatismo por Reperfusão/sangue , Superóxido Dismutase/metabolismo , Xantina Oxidase/sangue , Xantina Oxidase/metabolismo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...