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1.
Eur Rev Med Pharmacol Sci ; 27(14): 6718-6727, 2023 07.
Artigo em Inglês | MEDLINE | ID: mdl-37522683

RESUMO

OBJECTIVE: Berberine is a plant alkaloid known to exert positive metabolic effects. Human studies have confirmed its ability to improve the lipid and glycemic profile. This study aimed to evaluate the potential benefit of oral supplementation of Berberine PhytosomeTM (2 tablets/day, 550 mg/tablet) on the metabolic profile of subjects with impaired fasting blood glucose (IFG). PATIENTS AND METHODS: A total of 49 overweight subjects, 28 females and 21 males, were randomly assigned to either the supplemented group (n=24) or placebo (n=25). We considered glycemia as the primary endpoint and total cholesterol, high-density lipoprotein (HDL), total cholesterol/HLD, low-density lipoprotein (LDL), LDL/HDL, triglycerides, insulin, glycated hemoglobin, Homeostasis Model Assessment (HOMA), ApoA, ApoB, ApoB/ApoA, androgen suppression treatment (AST), alternative lengthening of telomeres (ALT), gamma-glutamyl transferase (GGT), creatinine, and body composition by dual-energy X-ray absorptiometry (DXA) as secondary endpoints. These parameters have been assessed at baseline, after 30 days, and after 60 days. RESULTS: After two months of treatment, through the use of linear mixed effect models, a statistically significant difference between supplemented and placebo groups was observed for glycemia [ß=-0.2495% C.I. (-0.47; -0.06), p=0.004], total cholesterol [ß=-0.25, 95% C.I. (-0.45; -0.04), p=0.05], total cholesterol/HDL [ß=-0.25, 95% C.I. (-0.43; -0.06), p=0.04], triglycerides [ß=-0.14, 95% C.I. (-0.25; -0.02), p=0.05], insulin [ß=-1.78, 95% C.I. (-2.87; -0.66), p=0.009], ApoB/ApoA [ß=-0.08, 95% C.I. (-0.13; -03), p=0.004], Visceral adipose tissue (VAT) [ß=-91.50, 95% C.I. (-132.60; -48.19), p<0.0001] and fat mass [ß=-945.56, 95% C.I. (-1,424.42; -441.57), p=0.004]. CONCLUSIONS: The use of berberine had no adverse events, supporting its use as a natural alternative to pharmacological therapies in the case of IFG.


Assuntos
Berberina , Sobrepeso , Masculino , Feminino , Humanos , Sobrepeso/tratamento farmacológico , Glicemia/metabolismo , Berberina/uso terapêutico , Fosfolipídeos , Triglicerídeos , Insulina , Lipoproteínas HDL , Colesterol , Apolipoproteínas A , Apolipoproteínas B , Jejum , Método Duplo-Cego
2.
Artigo em Inglês | MEDLINE | ID: mdl-30723511

RESUMO

The aim of the present study is to evaluate the effects of 60-day artichoke leaf extract (ALE) supplementation (250mg, twice daily) on cytokines levels, natural killer cell (NK) response, and lipo-metabolic profile (HDL, LDL, and total-cholesterol, triglycerides (TG), ApoB, ApoA, lipid accumulation product (LAP), glucose, insulin, and homeostasis model assessment of insulin resistance (HOMA-IR)) in twenty adults (9/11 males/females, age=49.10 ± 13.74 years, and BMI=33.12 ± 5.14 kg/m2) with low HDL-C and mild hypercholesterolemia. Hierarchical generalized linear model, adjusted for sex, BMI, and age, has been used to evaluate pre-post treatment changes. A significant increase for HDL-C (ß=0.14, p=0.0008) and MCP-1 (ß=144.77, p=0.004) and a significant decrease for ApoB/ApoA (ß=-0.07, p=0.03), total-C/HDL-C ratio (ß=-0.58, p<0.001), and NK response at stimulus low (ß=0.43, p=0.04), medium (ß=0.40, p<0.001), and high (ß=0.42, p=0.001) have been found. These results support the benefits of ALE supplementation on metabolic profile.

3.
Adv Gerontol ; 32(6): 1023-1033, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-32160444

RESUMO

We compare bioimpedance analysis (BIA) with dual-energy X-ray absorptiometry (DXA) in the assessment of free fat mass (FFM), fat mass (FM) and percentage of body fat under different conditions in relation to age categories, hydration parameters, body mass index (BMI) and sarcopenia. A cross-sectional analysis of body composition was estimated by BIA and DXA in 379 hospitalized elderly patients. In addition, estimates of FFM, FM and percentage of body fat were investigated across different conditions. Paired t-tests, Bland-Altman plot and intraclass correlation coefficient analysis were used to compare methods. Data showed an underestimation of means (BIA versus DXA) of FFM (women: 0,97 kg, p<0,01; men: 1,99 kg; p<0,01), and an overestimation of both the FM (women: +1,11 kg; p<0,01; men: +1,67 kg; p<0,01) and percentage of body fat (women: +2,07 %, p<0,01; men: +2,82 %, p<0,01). BIA underestimated FFM and overestimated FM and percentage of body fat in patients from the age group of 75 to 85 years, in patients with a total body water content <60%, in underweight and normal weight patients and in patients with sarcopenia (p<0,01). The intraclass coefficient results were indicative of poor reproducibility between BIA and DXA for FFM (women: +0,197; men: +0,250) and FM (women: +0,141; men +0,144). BIA is a good alternative for estimation of FFM and FM only in overweight or obese patients or in patients with good hydration status. BIA, on the other hand, is not an accurate method for assessing FFM in sarcopenic patients.


Assuntos
Absorciometria de Fóton , Composição Corporal , Impedância Elétrica , Idoso , Idoso de 80 Anos ou mais , Estudos de Coortes , Estudos Transversais , Feminino , Humanos , Masculino , Reprodutibilidade dos Testes
4.
Eur Rev Med Pharmacol Sci ; 21(22): 5258-5263, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-29228442

RESUMO

Standard pharmacological treatment of musculoskeletal conditions is often associated with relevant side effects. Botanical preparations endowed with a good tolerability profile, therefore, could have a role in the management of these disorders. Among different natural products, Boswellia serrata extracts have long been used for the treatment of musculoskeletal disorders, given their marked anti-inflammatory activity and their ability to promote tissue regeneration. However, standard preparations of Boswellia serrata show overall modest pharmacokinetic properties, a limitation which may ultimately lead to reduced efficacy. In an effort to improve the pharmacokinetic properties, Casperome®, a lecithin-based formulation of Boswellia serrata extract representing the whole natural bouquet, has been developed. This formulation was effective in the treatment of Achilles tendonitis, epicondylitis, radiculopathies, ankle sprains and sport injuries as shown in several clinical studies, the majority of which with a randomized design and all evaluating a number of well-recognized parameters of efficacy for the therapy of musculoskeletal disorder. All studies were consistent in showing a prompt decrease of pain and improvement of functionality of the affected area after supplementation with Casperome®, without any relevant adverse effect. Remarkably, these symptomatic improvements were paralleled by reduced plasmatic levels of inflammatory markers and by a diminished need for rescue analgesics. On these bases, Casperome® may have a role in the treatment of musculoskeletal disorders. Clinical studies in other similar conditions (e.g., osteoarthritis) appear warranted to further investigate the efficacy of this botanical product in more specific settings.


Assuntos
Doenças Musculoesqueléticas/tratamento farmacológico , Triterpenos/administração & dosagem , Triterpenos/uso terapêutico , Boswellia , Sistemas de Liberação de Medicamentos , Humanos , Extratos Vegetais/farmacologia , Triterpenos/farmacocinética
5.
Cancer Chemother Pharmacol ; 65(4): 625-39, 2010 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-19784839

RESUMO

PURPOSE: Comparative pharmacokinetic (PK) analysis of the mTOR inhibitor RAD001 (everolimus) in rats and mice. METHODS: Blood cell partitioning, plasma protein binding and PK parameters of RAD001 in blood and tissues (including brain) of both mice and rats were determined. PK modeling predicted plasma/blood and tumor levels from a variety of regimens and these were compared with the known human PK profile. DCE-MRI was used to compare tumor vascularity between mice and rats. Estimation of IC50 values in vitro and ED50 values in vivo were used to provide an indication of anti-tumor activity. RESULTS: The PK properties of RAD001 differed between mice and rats, including erythrocyte partitioning, plasma protein binding, plasma/blood t(1/2), oral bioavailability, volume of distribution, tissue/tumor penetration and elimination. Modeling of tumor and blood/plasma PK suggested that in mice, multiple daily administrations result in a 2-fold increase in tumor levels of RAD001 at steady state, whereas in rats, a 7.9-fold increase would occur. Weekly high-dose regimens were predicted not to facilitate tumor accumulation in either species. Total tumor levels of RAD001 were four- to eight-fold greater in rats than in mice. Rat tumors had a >2-fold greater plasma content and permeability compared to mouse tumors, which could contribute to differences in tumor drug uptake. Maximal antitumor effects (T/C of 0.04-0.35) were observed in both species after daily administration with similar C(max) and AUC values of unbound (free) RAD001. These free levels of RAD001 are exceeded in serum from cancer patients receiving clinically beneficial daily regimens. In rodents, brain penetration of RAD001 was poor, but was dose-dependent and showed over-proportional uptake in rats with a longer t(1/2) compared to the systemic circulation. CONCLUSIONS: The PK of RAD001 differed between mice and rats, with rats having a PK profile closer to that of humans. High intermittent doses of RAD001 may be more appropriate for treatment of brain tumors.


Assuntos
Imunossupressores/farmacocinética , Neoplasias Experimentais/metabolismo , Sirolimo/análogos & derivados , Animais , Área Sob a Curva , Linhagem Celular Tumoral , Everolimo , Fezes/química , Feminino , Humanos , Imunossupressores/sangue , Imunossupressores/urina , Masculino , Taxa de Depuração Metabólica , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Neoplasias Experimentais/sangue , Neoplasias Experimentais/urina , Ratos , Ratos Endogâmicos BN , Ratos Endogâmicos Lew , Sirolimo/farmacocinética , Especificidade da Espécie , Fatores de Tempo , Distribuição Tecidual , Transplante Heterólogo
6.
Artigo em Inglês | MEDLINE | ID: mdl-18811057

RESUMO

Development of new drugs and optimal application of the drugs currently in use in clinical chemotherapy requires the application of biomarkers. Ideally, these biomarkers would stratify patients so that only those patients likely to respond to a particular therapy receive that therapy. However, that is not always feasible, and an alternative is to make use of early response biomarkers to determine the responding population. In this paper, a number of generic (i.e. not necessarily specific to the action mechanism of the compound) early-response biomarkers are discussed and compared in different models and with three compounds with quite different mechanisms of action: a VEGF-R inhibitor (PTK787), an mTOR inhibitor (RAD001) and a microtubule stabiliser (EPO906). The methods include noninvasive DCE-MRI and PET imaging for measuring tumour vascularity, metabolism and proliferation, as well as the minimally invasive WIN method for measuring tumour interstitial pressure (IFP). The data show that drug-induced changes in IFP (delta IFP) involve mechanism-dependent changes in the tumour vascular architecture, and that delta IFP may be considered a universal generic early-response marker of tumour response to therapy.


Assuntos
Biomarcadores Tumorais/metabolismo , Neoplasias Experimentais/tratamento farmacológico , Neoplasias Experimentais/metabolismo , Animais , Antineoplásicos/uso terapêutico , Linhagem Celular Tumoral , Líquido Extracelular/fisiologia , Humanos , Imuno-Histoquímica , Imageamento por Ressonância Magnética , Camundongos , Camundongos Endogâmicos C3H , Camundongos Endogâmicos C57BL , Camundongos Nus , Transplante de Neoplasias , Neoplasias Experimentais/diagnóstico por imagem , Neoplasias Experimentais/fisiopatologia , Tomografia por Emissão de Pósitrons , Pressão , Ratos , Ratos Endogâmicos BN , Transplante Heterólogo
7.
Contrast Media Mol Imaging ; 1(1): 30-9, 2006.
Artigo em Inglês | MEDLINE | ID: mdl-17193598

RESUMO

{Fe[Gd(2)bpy(DTTA)(2)(H(2)O)(4)](3)}(4-) is a self-assembled, metallostar-structured potential MRI contrast agent, with six efficiently relaxing Gd(3+) centres confined into a small molecular space. Its proton relaxivity is particularly remarkable at very high magnetic fields (r(1) = 15.8 mM(-1) s(-1) at 200 MHz, 37 degrees C, in H(2)O). Here we report the first in vivo MRI feasibility study, complemented with dynamic gamma scintigraphic imaging and biodistribution experiments using the (153)Sm-enriched compound. Comparative MRI studies have been performed at 4.7 T in mice with the metallostar and the small molecular weight contrast agent gadolinium(III)-1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetate ([Gd(DOTA)(H(2)O)](-) = GdDOTA). The metallostar was well tolerated by the animals at the concentrations of 0.0500 (high dose) and 0.0125 (low dose) mmol Gd kg(-1) body weight; (BW). The signal enhancement in the inversion recovery fast low angle shot (IR FLASH) images after the high-dose metallostar injection was considerably higher than after GdDOTA injection (0.1 mmol Gd kg(-1) BW), despite the higher dose of the latter. The high-dose metallostar injection resulted in a greater drop in the spin-lattice relaxation time (T(1)), as calculated from the inversion recovery true fast imaging with steady-state precession (IR TrueFISP) data for various tissues, than the GdDOTA or the low dose metallostar injection. In summary, these studies have confirmed that the approximately four times higher relaxivity measured in vitro for the metallostar is retained under in vivo conditions. The pharmacokinetics of the metallostar was found to be similar to that of GdDOTA, involving fast renal clearance, a leakage to the extracellular space in the muscle tissue and no leakage to the brain. As expected on the basis of its moderate molecular weight, the metallostar does not function as a blood pool agent. The dynamic gamma scintigraphic studies performed in Wistar rats with the metallostar compound having (153)Sm enrichment also proved the renal elimination pathway. The biodistribution experiments are in full accordance with the MR and scintigraphic imaging. At 15 min post-injection the activity is primarily localized in the urine, while at 24 h post-injection almost all radioactivity is cleared from tissues and organs.


Assuntos
Compostos Ferrosos/síntese química , Compostos Ferrosos/farmacocinética , Gadolínio/química , Gadolínio/farmacocinética , Imageamento por Ressonância Magnética/métodos , Compostos Organometálicos/síntese química , Compostos Organometálicos/farmacocinética , Animais , Meios de Contraste/administração & dosagem , Meios de Contraste/efeitos adversos , Meios de Contraste/química , Meios de Contraste/farmacocinética , Relação Dose-Resposta a Droga , Feminino , Gadolínio/administração & dosagem , Gadolínio/efeitos adversos , Frequência Cardíaca/efeitos dos fármacos , Compostos Heterocíclicos/administração & dosagem , Compostos Heterocíclicos/efeitos adversos , Compostos Heterocíclicos/farmacocinética , Camundongos , Camundongos Endogâmicos C57BL , Modelos Moleculares , Compostos Organometálicos/administração & dosagem , Compostos Organometálicos/efeitos adversos , Cintilografia/métodos , Ratos , Ratos Wistar , Respiração/efeitos dos fármacos , Distribuição Tecidual
8.
Phys Rev E Stat Nonlin Soft Matter Phys ; 70(4 Pt 2): 046118, 2004 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-15600471

RESUMO

We study a two-state symmetric noise, with a given waiting time distribution psi (tau) , and focus our attention on the connection between the four-time and two-time correlation functions. The transition of psi (tau) from the exponential to the nonexponential condition yields the breakdown of the usual factorization condition of high-order correlation functions, as well as the birth of aging effects. We discuss the subtle connections between these two properties and establish the condition that the Liouville-like approach has to satisfy in order to produce a correct description of the resulting diffusion process.

10.
Phys Rev E Stat Nonlin Soft Matter Phys ; 67(6 Pt 1): 062901, 2003 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-16241281

RESUMO

We analyze RR heartbeat sequences with a dynamic model that satisfactorily reproduces both the long- and the short-time statistical properties of heart beating. These properties are expressed quantitatively by means of two significant parameters, the scaling delta concerning the asymptotic effects of long-range correlation, and the quantity 1-pi establishing the amount of uncorrelated fluctuations. We find a correlation between the position in the phase space (delta, pi) of patients with congestive heart failure and their mortality risk.


Assuntos
Biofísica/métodos , Insuficiência Cardíaca/mortalidade , Insuficiência Cardíaca/fisiopatologia , Fenômenos Fisiológicos Cardiovasculares , Cardiopatias/fisiopatologia , Frequência Cardíaca , Humanos , Modelos Biológicos , Modelos Estatísticos , Análise Multivariada , Dinâmica não Linear , Risco , Processamento de Sinais Assistido por Computador , Análise de Sobrevida , Sístole , Tempo
11.
Phys Rev E Stat Nonlin Soft Matter Phys ; 66(1 Pt 2): 015101, 2002 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-12241407

RESUMO

We prove that the Lévy walk is characterized by bilinear scaling. This effect mirrors the existence of a form of aging that does not require the adoption of nonstationary conditions.

12.
Phys Rev E Stat Nonlin Soft Matter Phys ; 65(4 Pt 1): 041926, 2002 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-12005892

RESUMO

We describe two types of memory and illustrate each using artificial and actual heartbeat data sets. The first type of memory, yielding anomalous diffusion, implies the inverse power-law nature of the waiting time distribution and the second the correlation among distinct times, and consequently also the occurrence of many pseudoevents, namely, not genuinely random events. Using the method of diffusion entropy analysis, we establish the scaling that would be determined by the real events alone. We prove that the heart beating of healthy patients reveals the existence of many more pseudoevents than in the patients with congestive heart failure.


Assuntos
Frequência Cardíaca/fisiologia , Memória/fisiologia , Simulação por Computador , Eletrocardiografia/estatística & dados numéricos , Entropia , Insuficiência Cardíaca/fisiopatologia , Humanos , Modelos Estatísticos
13.
J Cereb Blood Flow Metab ; 21(7): 857-64, 2001 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-11435798

RESUMO

There is increasing evidence that erythropoietin (Epo) has a protective function in cerebral ischemia. When used for treatment, high Epo plasma levels associated with increases in blood viscosity, however, may counteract beneficial effects of Epo in brain ischemia. The authors generated two transgenic mouse lines that overexpress human Epo preferentially, but not exclusively, in neuronal cells. In mouse line tg21, a fourfold increase of Epo protein level was found in brain only, whereas line tg6 showed a dramatic increase of cerebral and systemic transgene expression resulting in hematocrit levels of 80%. Cerebral blood flow (CBF), as determined by bolus tracking magnetic resonance imaging, was not altered in the tg6 line. The time-to-peak interval for the tracer, however, increased approximately threefold in polyglobulic tg6 mice. Immunohistochemical analysis revealed an increase in dilated vessels in tg6 mice, providing an explanation for unaltered CBF in polyglobulic animals. Permanent occlusion of the middle cerebral artery (pMCAO) led to similar perfusion deficits in wild-type, tg6, and tg21 mice. Compared with wild-type controls, infarct volumes were not significantly smaller (22%) in tg21 animals 24 hours after pMCAO, but were 49% enlarged (P < 0.05) in polyglobulic tg6 mice. In the latter animals, elevated numbers of Mac-1 immunoreactive cells in infarcted tissue suggested that leukocyte infiltration contributed to enlarged infarct volume. The current results indicate that moderately increased brain levels of Epo in tg21 transgenic mice were not sufficient to provide significant tissue protection after pMCAO. The results with tg6 mice indicate that systemic chronic treatment with Epo associated with elevated hematocrit might deteriorate outcome after stroke either because of the elevated hematocrit or other chronic effects.


Assuntos
Infarto Cerebral/patologia , Eritropoetina/genética , Expressão Gênica , Animais , Velocidade do Fluxo Sanguíneo , Viscosidade Sanguínea , Encéfalo/irrigação sanguínea , Encéfalo/metabolismo , Encéfalo/patologia , Isquemia Encefálica/metabolismo , Antígenos CD11/análise , Infarto Cerebral/metabolismo , Endotélio Vascular/química , Eritropoetina/fisiologia , Hematócrito , Humanos , Laminina/análise , Macrófagos/patologia , Imageamento por Ressonância Magnética , Masculino , Camundongos , Camundongos Transgênicos , Artéria Cerebral Média/cirurgia , Monócitos/patologia , Neurônios/metabolismo , Molécula-1 de Adesão Celular Endotelial a Plaquetas/análise , Molécula 1 de Adesão de Célula Vascular/análise
14.
Anat Rec ; 265(2): 85-100, 2001 04.
Artigo em Inglês | MEDLINE | ID: mdl-11323771

RESUMO

In recent years, in vivo magnetic resonance (MR) methods have become established tools in the drug discovery and development process. In this article, the role of MR imaging (MRI) in the preclinical evaluation of drugs in animal models of diseases is illustrated on the basis of selected examples. The individual sections are devoted to applications of anatomic, physiologic, and "molecular" imaging providing, respectively, structural-morphological, functional, and target-specific information. The impact of these developments upon clinical drug evaluation is also briefly addressed. The main advantages of MRI are versatility, allowing a comprehensive characterization of a disease state and of the corresponding drug intervention; high spatial resolution; and noninvasiveness, enabling repeated measurements. Successful applications in drug discovery exploit one or several of these aspects. Additionally, MRI is contributing to strengthen the link between preclinical and clinical drug research.


Assuntos
Desenho de Fármacos , Avaliação Pré-Clínica de Medicamentos/métodos , Imageamento por Ressonância Magnética/métodos , Doenças dos Animais/tratamento farmacológico , Doenças dos Animais/metabolismo , Animais , Modelos Animais de Doenças , Drogas em Investigação/uso terapêutico , Humanos , Camundongos , Coelhos , Ratos
15.
Br J Pharmacol ; 132(1): 234-40, 2001 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-11156582

RESUMO

1. Endothelin-1 (ET-1) may play a role in myocardial ischaemia/reperfusion injury because both the release and vasoconstrictor effect of ET-1 are increased after ischaemia. Since the increased vasoconstrictor effect of ET-1 can be mediated by ET-1-induced release of thromboxane A(2) (TXA(2)), the aim of this study was to test whether combined blockade of ET and TXA(2) receptors protects the coronary flow, contractile performance, and cardiac energy metabolism during ischaemia and reperfusion. 2. Bosentan (antagonist for ET(A) and ET(B) receptors, 1 microM based on concentration-response curves of ET-1), SQ 30,741 (antagonist of TXA(2) receptors, 0.1 microM), or the combination thereof was administered to isolated perfused rat hearts undergoing 15 min of global ischaemia and 60 min of reperfusion. 3. Neither bosentan or SQ 30,741 alone, nor the combination thereof, improved the incomplete postischaemic recovery of coronary flow, left ventricular developed pressure, phosphocreatine, or ATP. However, they attenuated ischaemia-induced acidosis but this did not translate into a measurable effect on haemodynamic or metabolic variables. 4. Thus, combined blockade of ET and TXA(2) receptors does not protect the coronary flow, contractile performance, and cardiac energy metabolism during ischaemia and reperfusion in isolated perfused rat hearts. This finding suggests that neither ET-1 nor ET-1-induced release of TXA(2) play a major role in the postischaemic recovery of the cardiac contractile function and energy metabolism.


Assuntos
Antagonistas dos Receptores de Endotelina , Contração Miocárdica/efeitos dos fármacos , Traumatismo por Reperfusão Miocárdica/prevenção & controle , Receptores de Tromboxanos/antagonistas & inibidores , Trifosfato de Adenosina/metabolismo , Animais , Pressão Sanguínea/efeitos dos fármacos , Bosentana , Circulação Coronária/efeitos dos fármacos , Relação Dose-Resposta a Droga , Técnicas In Vitro , Espectroscopia de Ressonância Magnética , Masculino , Traumatismo por Reperfusão Miocárdica/fisiopatologia , Miocárdio/metabolismo , Fosfocreatina/metabolismo , Ratos , Ratos Sprague-Dawley , Receptor de Endotelina A , Sulfonamidas/farmacologia , Tromboxano A2/análogos & derivados , Tromboxano A2/farmacologia , Função Ventricular Esquerda/efeitos dos fármacos , Pressão Ventricular/efeitos dos fármacos
16.
Am J Pathol ; 157(5): 1473-83, 2000 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-11073808

RESUMO

Vascular endothelial growth factor (VEGF), a key regulator of vasculogenesis and embryonic angiogenesis, was recently found to be up-regulated in an animal model of stroke. Unlike VEGF, angiopoietin (Ang)-1 and -2, their receptor tie-2, and the associated receptor tie-1 exert their functions at later stages of vascular development, i.e., during vascular remodeling and maturation. To assess the role of the angiopoietin/tie family in ischemia-triggered angiogenesis we analyzed their temporal and spatial expression pattern after middle cerebral artery occlusion (MCAO) using in situ hybridization and immunohistochemistry. Ang-1 mRNA was constitutively expressed in a subset of glial and neuronal cells with no apparent change in expression after MCAO. Ang-2 mRNA was up-regulated 6 hours after MCAO and was mainly observed in endothelial cell (EC) cord tips in the peri-infarct and infarct area. Up-regulation of both Ang-2 and VEGF coincided with EC proliferation. Interestingly, EC proliferation was preceded by a transient period of EC apoptosis, correlating with a change in VEGF/Ang-2 balance. Our observation of specific stages of vascular regression and growth after MCAO are in agreement with recent findings suggesting a dual role of Ang-2 in blood vessel formation, depending on the availability of VEGF.


Assuntos
Arteriopatias Oclusivas/metabolismo , Artérias Cerebrais , Glicoproteínas de Membrana/metabolismo , Proteínas/metabolismo , Receptores Proteína Tirosina Quinases/metabolismo , Receptores de Superfície Celular/metabolismo , Angiopoietina-1 , Angiopoietina-2 , Animais , Apoptose , Arteriopatias Oclusivas/fisiopatologia , Vasos Sanguíneos/fisiopatologia , Divisão Celular , Endotélio Vascular/patologia , Endotélio Vascular/fisiopatologia , Imuno-Histoquímica , Hibridização In Situ , Masculino , Glicoproteínas de Membrana/genética , Proteínas/genética , RNA Mensageiro/metabolismo , Ratos , Ratos Endogâmicos F344 , Receptores Proteína Tirosina Quinases/genética , Receptor de TIE-1 , Receptor TIE-2 , Receptores de Superfície Celular/genética , Receptores de TIE
17.
Brain Res ; 882(1-2): 19-25, 2000 Nov 03.
Artigo em Inglês | MEDLINE | ID: mdl-11056180

RESUMO

BACKGROUND: Previous experimental work using in situ zymography has shown very early increased plasminogen activation in ischemic regions after 3 h of ischemia with and without reperfusion. The objective of the present study was to evaluate the time course and extent of plasminogen activation in long-term permanent focal cerebral ischemia. MATERIAL AND METHODS: The middle cerebral artery in male Fisher rats was irreversibly occluded by electrocoagulation. Duration of ischemia was 48, 72, and 168 h. Occlusion was controlled in vivo by MRI at day 2. Plasminogen activation was detected by in situ zymography of 10 microm cryosections with an overlay containing plasminogen and the plasmin substrate caseine. Areas of plasminogen activation were compared to structural lesions (immunohistochemical loss of microtubule-associated protein 2; MAP 2). RESULTS: Compared to controls, increased plasminogen activation was observed in the basal ganglia and the cortex of the ischemic hemisphere after 48, 72, and 168 h (affected area of basal ganglia: 44.5+/-21.9, 70.1+/-2.3 and 66.6+/-2.8%, respectively; affected area of cortex: 63.4+/-9.8, 67.7+/-0.7 and 64.0+/-3.7%, respectively). The duration of ischemia had no significant influence on the extent of plasminogen activation. Areas of increased plasminogen activation significantly overlapped with and exceeded areas of MAP 2 loss (P<0.005). DISCUSSION: Permanent focal cerebral ischemia leads to increased plasminogen activation in ischemic regions. This plasminogen activation remains elevated at persistent levels over days. It may contribute to extracellular matrix (ECM) disruption, secondary hemorrhage, and brain edema in subacute stages of ischemic stroke.


Assuntos
Gânglios da Base/metabolismo , Isquemia Encefálica/metabolismo , Córtex Cerebral/metabolismo , Infarto da Artéria Cerebral Média/metabolismo , Proteínas Associadas aos Microtúbulos/metabolismo , Plasminogênio/metabolismo , Animais , Masculino , Ratos , Ratos Endogâmicos F344
18.
Cell Mol Biol (Noisy-le-grand) ; 46(1): 53-62, 2000 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-10726971

RESUMO

In primary neuronal-astrocyte cultures from mouse brain, ischemic conditions were simulated by combined oxygen-glucose deprival (OGD) for 2 hrs. This treatment resulted in near complete neuronal damage 24 hrs. later and was accompanied by DNA degradation and apoptotic nuclear morphology. Since caspases are key enzymes in the propagation and execution of programmed cell death, we evaluated the effect of the caspase inhibitor z-VAD-fmk. Damage following 2 hrs. OGD could be reduced by up to 56% with z-VAD-fmk (p<0.05). DNA-fragmentation and caspase activation has been also reported in an in vivo model of cerebral ischemia imitating human stroke. In this model the middle cerebral artery (MCA) is permanently occluded resulting in focal cerebral ischemia and subsequent infarction. Since z-VAD.fmk does not penetrate the blood-brain barrier it was applied intraventricularly as a bolus injection given 30 min. before MCA occlusion which was followed by 24 hrs. of infusion. Infarct volume was determined 48 hrs. after MCA occlusion by means of in vivo magnetic resonance imaging. Z-VAD.fmk dose dependently reduced infarct volume reaching a significant decrease of the cortical infarct by 45% when given as a 120 ng bolus followed by 40 ng/hr. infusion (p<0.05). In summary, our study supports the concept that caspase inhibitors are beneficial in brain ischemia.


Assuntos
Clorometilcetonas de Aminoácidos/farmacologia , Apoptose , Isquemia Encefálica/metabolismo , Inibidores de Caspase , Inibidores Enzimáticos/farmacologia , Animais , Astrócitos , Encéfalo/metabolismo , Encéfalo/patologia , Maleato de Dizocilpina/farmacologia , Glucose/metabolismo , Imuno-Histoquímica , Marcação In Situ das Extremidades Cortadas , L-Lactato Desidrogenase/metabolismo , Imageamento por Ressonância Magnética , Camundongos , Fármacos Neuroprotetores/farmacologia , Ratos , Ratos Endogâmicos F344 , Acidente Vascular Cerebral/metabolismo
20.
J Cell Biol ; 151(7): 1537-48, 2000 Dec 25.
Artigo em Inglês | MEDLINE | ID: mdl-11134081

RESUMO

Ras is a universal eukaryotic intracellular protein integrating extracellular signals from multiple receptor types. To investigate its role in the adult central nervous system, constitutively activated V12-Ha-Ras was expressed selectively in neurons of transgenic mice via a synapsin promoter. Ras-transgene protein expression increased postnatally, reaching a four- to fivefold elevation at day 40 and persisting at this level, thereafter. Neuronal Ras was constitutively active and a corresponding activating phosphorylation of mitogen-activated kinase was observed, but there were no changes in the activity of phosphoinositide 3-kinase, the phosphorylation of its target kinase Akt/PKB, or expression of the anti-apoptotic proteins Bcl-2 or Bcl-X(L). Neuronal Ras activation did not alter the total number of neurons, but induced cell soma hypertrophy, which resulted in a 14.5% increase of total brain volume. Choline acetyltransferase and tyrosine hydroxylase activities were increased, as well as neuropeptide Y expression. Degeneration of motorneurons was completely prevented after facial nerve lesion in Ras-transgenic mice. Furthermore, neurotoxin-induced degeneration of dopaminergic substantia nigra neurons and their striatal projections was greatly attenuated. Thus, the Ras signaling pathway mimics neurotrophic effects and triggers neuroprotective mechanisms in adult mice. Neuronal Ras activation might become a tool to stabilize donor neurons for neural transplantation and to protect neuronal populations in neurodegenerative diseases.


Assuntos
Hipertrofia/patologia , Neurônios Motores/metabolismo , Neurônios Motores/patologia , Doenças Neurodegenerativas/patologia , Fármacos Neuroprotetores/metabolismo , Proteínas Serina-Treonina Quinases , Proteínas Proto-Oncogênicas p21(ras)/metabolismo , 1-Metil-4-Fenil-1,2,3,6-Tetra-Hidropiridina/farmacologia , 1-Metil-4-fenilpiridínio/farmacologia , Animais , Axotomia , Encéfalo/efeitos dos fármacos , Encéfalo/enzimologia , Encéfalo/patologia , Contagem de Células , Tamanho Celular , Células Cultivadas , Colina O-Acetiltransferase/metabolismo , Ativação Enzimática , Hipertrofia/enzimologia , Camundongos , Camundongos Transgênicos , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Neurônios Motores/efeitos dos fármacos , Neurônios Motores/enzimologia , Mutação/genética , Doenças Neurodegenerativas/enzimologia , Neuropeptídeo Y/genética , Neuropeptídeo Y/metabolismo , Oxidopamina/farmacologia , Fosfatidilinositol 3-Quinases/metabolismo , Fosforilação , Proteínas Proto-Oncogênicas/metabolismo , Proteínas Proto-Oncogênicas c-akt , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Proteínas Proto-Oncogênicas p21(ras)/genética , RNA Mensageiro/análise , RNA Mensageiro/genética , Transdução de Sinais/efeitos dos fármacos , Substância Negra/efeitos dos fármacos , Substância Negra/patologia , Tirosina 3-Mono-Oxigenase/metabolismo
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