Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 14 de 14
Filtrar
Mais filtros








Intervalo de ano de publicação
1.
Medicina (B Aires) ; 84(2): 206-220, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38683505

RESUMO

INTRODUCTION: Chia and flax seeds are rich in alphalinolenic acid (ALA), which is bioconverted into the active derivatives eicosapentaenoic (EPA) and docosahexaenoic (DHA) having multiple beneficial effects. However, there is limited knowledge about the antiinflammatory effects of chia and flax integral flours diets rich in ALA. OBJECTIVE: The study aimed to evaluate the antiinflammatory effect of dietary supplementation with integral chia and flax flours in a murine model of LPSinduced systemic inflammation. METHODS: Balb/c mice were distributed into three groups: diet A (control), diet B (supplemented with integral chia flour), and diet C (supplemented with integral flax flour). Nutritional, hematological, and biochemical determinations were performed. ALA, EPA, and DHA were assessed by GC-MS in the liver, brain, cardiac and skeletal muscles. NF-kB immunoassays were performed in kidney, liver, and peritoneal macrophages, respectively. The phagocytic capacity was determined in peritoneal macrophages and the expression of the pro- and anti-inflammatory cytokines was assessed by RT-qPCR in the kidney, liver, and spleen. RESULTS: Diets B and C exhibited optimal nutritional adequacy and caused increased levels of ALA, EPA, and DHA in critical tissues compared to the control. The phagocytic capacity of murine peritoneal macrophages (p< 0.01) and IL-10 transcription increased, whereas the expression of NF-κB, IL-1Β, IL-6, and TNF-α decreased in animals fed both experimental diets. CONCLUSIONS: This work contributes to the current knowledge of the anti-inflammatory effects of chia and flax integral flours rich in ALA and reinforces the health advantages of their consumption.


Introducción: Las semillas de chía y lino son ricas en ácido alfa-linolénico (ALA), sus derivados activos eicosapentaenoico (EPA) y docosahexaenoico (DHA) ejercen probados efectos beneficiosos. Existe un conocimiento limitado sobre los efectos protectores de ambas semillas bajo la forma de harinas integrales, siendo de particular interés el efecto antiinflamatorio. OBJETIVO: El objetivo de este trabajo fue evaluar el efecto antiinflamatorio de la suplementación dietaria con harinas integrales de semillas de chía y lino en un modelo murino de inflamación sistémica inducido por LPS. Métodos: Ratones de la cepa Balb/c fueron distribuidos en tres grupos: dieta A (control), dieta B (suplementada con harina integral de chía) y dieta C (suplementada con harina integral de lino). Se efecturaron determinaciones nutricionales, hematológicas y bioquímicas. El contenido de ALA, EPA y DHA en hígado, cerebro, corazón y músculo esquelético se determinó por cromatografía GC-MS. Se realizó la inmunodetección de NF-kB en macrófagos peritoneales, riñón e hígado. Se determinó la capacidad fagocítica de macrófagos peritoneales y se evaluó la expresión de citoquinas pro y antiinflamatorias por RT-qPCR en riñón, hígado y bazo. RESULTADOS: Las dietas B y C mostraron una adecuación nutricional óptima y generaron niveles elevados de ALA, EPA y DHA en tejidos críticos. La capacidad fagocítica de los macrófagos peritoneales (p< 0.01) y la transcripción de IL-10 aumentó, mientras que la expresión de NF-κB, IL-1Β, IL-6 y TNF-α disminuyó en animales de los grupos B y C. CONCLUSIONES: Este trabajo contribuye al conocimiento actual de los efectos antiinflamatorios de ambas harinas integrales y refuerza los beneficios de su consumo.


Assuntos
Suplementos Nutricionais , Linho , Inflamação , Camundongos Endogâmicos BALB C , Animais , Inflamação/dietoterapia , Camundongos , Farinha/análise , Citocinas/análise , Modelos Animais de Doenças , Masculino
2.
Antioxidants (Basel) ; 12(2)2023 Jan 19.
Artigo em Inglês | MEDLINE | ID: mdl-36829791

RESUMO

Microglia, the resident macrophage-like population in the CNS, plays an important role in the pathogenesis of many neurodegenerative disorders. Nectandra genus is known to produce different metabolites with anti-inflammatory, anti-oxidant and analgesic properties. Although the species Nectandra angustifolia is popularly used for the treatment of different types of inflammatory processes, its biological effects on neuroinflammation have not yet been addressed. In this study, we have investigated the role of a Nectandra angustifolia ethanolic extract (NaE) in lipopolysaccharide (LPS)-induced neuroinflammation in vitro and in vivo. In LPS-activated BV2 microglial cells, NaE significantly reduced the induced proinflammatory mediators TNF-α, IL-1ß, IL-6, COX-2 and iNOS, as well as NO accumulation, while it promoted IL-10 secretion and YM-1 expression. Likewise, reduced CD14 expression levels were detected in microglial cells in the NaE+LPS group. NaE also attenuated LPS-induced ROS and lipid peroxidation build-up in BV2 cells. Mechanistically, NaE prevented NF-κB and MAPKs phosphorylation, as well as NLRP3 upregulation when added before LPS stimulation, although it did not affect the level of some proteins related to antioxidant defense such as Keap-1 and HO-1. Additionally, we observed that NaE modulated some activated microglia functions, decreasing cell migration, without affecting their phagocytic capabilities. In LPS-injected mice, NaE pre-treatment markedly suppressed the up-regulated TNF-α, IL-6 and IL-1ß mRNA expression induced by LPS in brain. Our findings indicate that NaE is beneficial in preventing the neuroinflammatory response both in vivo and in vitro. NaE may regulate microglia homeostasis, not only restraining activation of LPS towards the M1 phenotype but promoting an M2 phenotype.

3.
Cancers (Basel) ; 13(12)2021 Jun 13.
Artigo em Inglês | MEDLINE | ID: mdl-34199164

RESUMO

Clear cell renal cell carcinoma (ccRCC) is the most common histological subtype of renal cell carcinoma (RCC). It is characterized by a high cell proliferation and the ability to store lipids. Previous studies have demonstrated the overexpression of enzymes associated with lipid metabolism, including stearoyl-CoA desaturase-1 (SCD-1), which increases the concentration of unsaturated fatty acids in tumor cells. In this work, we studied the expression of SCD-1 in primary ccRCC tumors, as well as in cell lines, to determine its influence on the tumor lipid composition and its role in cell proliferation. The lipidomic analyses of patient tumors showed that oleic acid (18:1n-9) is one of the major fatty acids, and it is particularly abundant in the neutral lipid fraction of the tumor core. Using a ccRCC cell line model and in vitro-generated chemical hypoxia, we show that SCD-1 is highly upregulated (up to 200-fold), and this causes an increase in the cellular level of 18:1n-9, which, in turn, accumulates in the neutral lipid fraction. The pharmacological inhibition of SCD-1 blocks 18:1n-9 synthesis and compromises the proliferation. The addition of exogenous 18:1n-9 to the cells reverses the effects of SCD-1 inhibition on cell proliferation. These data reinforce the role of SCD-1 as a possible therapeutic target.

4.
Future Med Chem ; 13(1): 13-23, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33243020

RESUMO

Background: Angiotensin II receptor blockers were designed as therapeutic agents to block the binding site of the angiotensin II receptor type 1 (AT1R). Methodology: The structure of telmisartan was modified by coordination to the biometal Zn(II), resulting in the compound ZnTelm. Its antihypertensive activity and cellular mechanisms in comparison to telmisartan were studied. Results: Compared with telmisartan, ZnTelm displayed stronger binding to AT1R (binding studies on AT1R-transfected human embryonic kidney cells) and a greater reduction of reactive oxygen species and cytosolic calcium concentration induced by angiotensin II. The antihypertensive activity of the complex (assessed in an N(G)-Nitro-L-arginine methyl ester-induced hypertension model) was significantly higher. ZnTelm also reduced hypertrophy in aortic artery rings and tubular collagen deposition. Conclusion: ZnTelm enhances the AT1R blockade and consequently its antihypertensive effect.


Assuntos
Anti-Hipertensivos/química , Complexos de Coordenação/química , Hipertensão/tratamento farmacológico , Receptor Tipo 1 de Angiotensina/metabolismo , Telmisartan/química , Zinco/química , Animais , Anti-Hipertensivos/farmacologia , Artérias/metabolismo , Cálcio/metabolismo , Linhagem Celular , Modelos Animais de Doenças , Humanos , Masculino , Ligação Proteica , Ratos Wistar , Espécies Reativas de Oxigênio/metabolismo , Receptor Tipo 1 de Angiotensina/genética , Telmisartan/farmacologia , Transfecção
5.
Biol Trace Elem Res ; 197(2): 454-463, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31863274

RESUMO

To improve the anticancer activity of telmisartan, its structure has been modified by Zn(II) complexation giving [Zn(Telm)2(H2O)2]·2H2O (ZnTelm). The cytotoxic effect was measured on the human lung cancer cells (A549) and on the lung fibroblast cells (MRC-5). The complex markedly improved anticancer activity (IC50 75 µM) of telmisartan (IC50 125 µM) or ZnSO4 (IC50 225 µM) and did not show toxicity on non-cancer cells, inducing oxidative stress with cellular ROS generation and GSH/GSSG decrease. Apoptosis was the dominant form of cell death for the complex. The Bax/Bcl-XL ratio was significantly increased as well as caspase-3 activation. Both the complex and the ligand bind to bovine serum albumin (BSA) and can be stored and transported by the protein but the interaction with the complex is greater. Telmisartan binds BSA by hydrophobic interactions while the interaction of ZnTelm occurs through van der Waals forces and hydrogen bonding. Therefore, it can be shown that the coordination complex ZnTelm improved the anticancer activity of the antihypertensive drug telmisartan (IC50 75 µM and 125 µM, respectively) and the interaction with BSA. Graphical Abstract Improvement of the anticancer activities of telmisartan by Zn(II) complexation and mechanisms of action. Intrinsic apoptotic pathway: induction ofoxidative stress and regulation of proteins related to apoptosis. The complex interacted with bovine serum albumin (BSA) and can be stored and transported by the protein.


Assuntos
Antineoplásicos , Apoptose , Antineoplásicos/farmacologia , Humanos , Espécies Reativas de Oxigênio , Soroalbumina Bovina/farmacologia , Telmisartan/farmacologia , Zinco/farmacologia
6.
Biol Trace Elem Res ; 186(2): 413-429, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-29651733

RESUMO

A new losartan [2-butyl-5-chloro-3-[[4-[2-(2H-tetrazol-5-yl)phenyl]phenyl]methyl]imidazol-4-yl]methanol zinc(II) complex [Zn(Los)Cl], was synthesized and characterized. The crystal structure was determined by x-ray diffraction methods. When aqueous solutions of the ligand and the metal were mixed, the known and more soluble powder [Zn(Los)2].3H2O (ZnLos) complex has been obtained. The interactions with phosphatases showed a concerted mechanism displayed by the Zn ions and ZnLos up to 500 µM concentration: a decrease of the acid phosphatase (AcP) associated with an increase in the alkaline phosphatase (ALP) activities. The complex and ZnSO4 showed a cytotoxic behavior on human lung A549 cancer cell line at concentrations higher than 75 µM with reactive oxygen species (ROS) generation and GSH (and GSH/GSSG ratio) depletion. Apoptotic cells were observed using terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) method, a mechanism accompanied by upregulation of BAX protein, downregulation of Bcl-XL and release of caspase-3. The BAX/Bcl-XL ratio was found to be significantly higher in cells exposure to ZnLos than cells treated with ZnSO4, in agreement with the higher apoptotic percentage of cells found for the complex. Cell death was found to be produced by apoptosis and no necrosis has been observed. On the contrary, losartan exerted low effects on phosphatases, produced some reduction of cancer cell viability (concentrations > 250 µM, number of apoptotic cells similar to the basal) with low ROS depletion, without alteration of the GSH/GSSG and low BAX/Bcl-XL ratios. In the MRC-5, normal lung fibroblasts cell line only ZnSO4 at concentrations higher than 200 µM displays cytotoxic effects. Graphical abstract Interaction of Zn with losartan. Activation of intrinsic apoptotic signaling pathway in lung cancer cells and effects on alkaline and acid phosphatases.


Assuntos
Fosfatase Ácida/metabolismo , Fosfatase Alcalina/metabolismo , Apoptose/efeitos dos fármacos , Complexos de Coordenação/farmacologia , Losartan/farmacologia , Zinco/farmacologia , Células A549 , Bloqueadores do Receptor Tipo 1 de Angiotensina II/química , Bloqueadores do Receptor Tipo 1 de Angiotensina II/farmacologia , Caspase 3/metabolismo , Complexos de Coordenação/química , Glutationa/metabolismo , Humanos , Losartan/química , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/patologia , Espécies Reativas de Oxigênio/metabolismo , Transdução de Sinais/efeitos dos fármacos , Zinco/química , Proteína X Associada a bcl-2/metabolismo , Proteína bcl-X/metabolismo
7.
Toxicol In Vitro ; 48: 205-220, 2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29408668

RESUMO

Azilsartan is the eighth approved member of angiotensin II receptor blockers for hypertension treatment. Considering that some drugs have additional effects when administered, we studied its effects and mechanisms of action on a human lung cancer cell line A549. We have also modified the structure of the drug by complexation with Zn(II) cation and assayed the anticancer effect. The crystal structure of the new binuclear Zn(II) complex, for short [Zn2(azil)2(H2O)4]·2H2O (ZnAzil), was determined by X-ray diffraction methods. The zinc ions are bridged by azilsartan ligands through their carboxylate oxygen and oxadiazol nitrogen atoms. The compounds were examined for their cytotoxic effects against human lung fibroblast (MRC5) and human lung cancer (A549) cell lines. Azilsartan displayed low cytotoxic effects at 150 µM concentrations in A549 human lung cancer cells but the higher effect measured for the Zn complex suggested that this compound may act as an anticancer agent. An apoptotic oxidative stress mechanism of action via the mitochondrial-dependent intrinsic pathway has been determined. Besides, the compounds exerted weak cytotoxic effects in the normal lung related cell line MRC5. Binding constants of the complex formed between each compound and bovine serum albumin (BSA) are in the intermediate range, hence suggesting that azilsartan and ZnAzil could be bonded and transported by BSA.


Assuntos
Antineoplásicos/farmacologia , Benzimidazóis/farmacologia , Oxidiazóis/farmacologia , Células A549 , Antineoplásicos/química , Antioxidantes/farmacologia , Apoptose/efeitos dos fármacos , Benzimidazóis/química , Fibroblastos/efeitos dos fármacos , Humanos , Modelos Moleculares , Necrose/induzido quimicamente , Necrose/patologia , Oxidiazóis/química , Ligação Proteica , Espécies Reativas de Oxigênio/metabolismo , Soroalbumina Bovina/química , Difração de Raios X , Zinco/química
8.
Rev. Fac. Med. Univ. Nac. Nordeste ; 36(3): 52-60, 2016. CD-ROM
Artigo em Espanhol | LILACS | ID: biblio-1052730

RESUMO

Los factores inducibles por hipoxia (HIFs) regulan la adaptación a la hipoxia (H) y protegen a las células induciendo la transcripción de múltiples genes. Se propone estudiar la expresión de las isoformas HIF1αy HIF2αen tejidos hematopoyéticos MO y Bz durante 15 días de Hipoxia Hipobárica (HH) relacionarlos con la cinética de expresión de EPO-R y factores determinantes de la eritropoyesis GATA-1 y NFE2. Se utilizaron ratones CF1, sometidos a HH 0,4 atm de 0 a 15 días. A cada tiempo, se extrajeron fémures y Bz para la obtención de extractos, fraccionamiento proteico e inmunoblotting. Se determinaron parámetros hematológicos standard. La apoptosis fue cuantificada por TUNEL. HIFαfue evaluado en sus dos isoformas. En MO y Bz el factor de transcripción aumenta y es mayor desde el día 1 de HH en Bz. Niveles máximos de HIF1αse verifican al día 3 en MO y a partir del día 5 en Bz. HIF2αen MO presenta expresión máxima al día 2 con posterior descenso, donde la MO retoma el control de la eritropoyesis. En Bz, HIF2 exhibe patrón irregular, conservando aumentos de su inmunodetección en función de la H. Epo-R se expresa desde día 1 en MO y Bz en un patrón similar de comportamiento a GATA-1. NFE2 tiene una cinética diferencial con progresión de ascenso en MO conforme aumentan los días de H observándose un máximo al día 15 mientras que el Bz muestra paulatino descenso en función de la adaptación medular a la H. Esto sugiere que en el Bz y MO se verifican procesos adaptativos coexistentes de expansión/sobrevivencia y apoptosis de progenitores eritroides. En Bz predomina una eritropoyesis compensatoria. En MO por el contrario predomina apoptosis temprana con posterior recomposición y control de la expansión del compartimiento eritroideo. HIF1 y HIF2 se sobreexpresan en ambos tejidos, sin embargo la eritropoyesis esplénica está ligada al control de HIF1αya que aparentemente HIF2αestaría asociada a la supervivencia de otros tipos celulares esplénicos durante el estrés hipóxicoPalabras clave: Hipoxia hipobárica; Factores Inducibles por Hipoxia; Eritropoyesis


Assuntos
Camundongos , Apoptose/fisiologia , Eritropoese , Hipóxia , Baço , Medula Óssea , Células , /métodos , /estatística & dados numéricos
9.
Exp Toxicol Pathol ; 67(10): 483-90, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26208869

RESUMO

Ipomoea carnea subsp. fistulosa (Convolvulaceae) causes poisoning of goats, sheep and cattle in many tropical and subtropical countries. The pathophysiology of this poisoning mainly involves an abnormal glycoprotein metabolism. The aim of this study was to describe the potential toxicity of I. carnea in a guinea pig model through its effect on hematopoiesis in a time course study of 40 days. Experimental poisoning was achieved by feeding animals with "small balls" prepared with milled leaves of I. carnea mixed with commercial crushed pellets for rodents. Hematologic and biochemical parameters, bone marrow and spleencellularities, histopathologic evaluations and lectin-histochemistrywere performed during the scheduled time of the study.The treatment with "small balls" caused significant changes in the weight of spleen, a notable decrease in peripheral red blood cells, and concomitantwith morphological and histopathologicalalterationsin hematopoietic tissues. Overall, the present study suggested that 20 days ofthis treatmentcouldbe enough to develop bone marrow hypoplasia and vacuolation of white cells of spleen, blood and lymph nodes with a transient erythropoietic contribution of the splenic niche.Moreover, this work provides a cheap and simple method for detecting preclinical cases of intoxication by I. carnea in livestock.


Assuntos
Hematopoese/efeitos dos fármacos , Ipomoea/toxicidade , Extratos Vegetais/toxicidade , Animais , Cobaias , Masculino , Microscopia Eletrônica de Varredura , Folhas de Planta/toxicidade
10.
J Control Release ; 214: 12-22, 2015 Sep 28.
Artigo em Inglês | MEDLINE | ID: mdl-26188153

RESUMO

Modern subunit vaccines require the development of new adjuvant strategies. Recently, we showed that CpG-ODN formulated with a liquid crystal nanostructure formed by self-assembly of 6-O-ascorbyl palmitate (Coa-ASC16) is an attractive system for promoting an antigen-specific immune response to weak antigens. Here, we showed that after subcutaneous injection of mice with near-infrared fluorescent dye-labeled OVA antigen formulated with Coa-ASC16, the dye-OVA was retained at the injection site for a longer period than when soluble dye-OVA was administered. Coa-ASC16 alone elicited a local inflammation, but how this material triggers this response has not been described yet. Although it is known that some materials used as a platform are not immunologically inert, very few studies have directly focused on this topic. In this study, we explored the underlying mechanisms concerning the interaction between Coa-ASC16 and the immune system and we found that the whole inflammatory response elicited by Coa-ASC16 (leukocyte recruitment and IL-1ß, IL-6 and IL-12 production) was dependent on the MyD88 protein. TLR2, TLR4, TLR7 and NLRP3-inflammasome signaling were not required for induction of this inflammatory response. Coa-ASC16 induced local release of self-DNA, and in TLR9-deficient mice IL-6 production was absent. In addition, Coa-ASC16 revealed an intrinsic adjuvant activity which was affected by MyD88 and IL-6 absence. Taken together these results indicate that Coa-ASC16 used as a vaccine platform is effective due to the combination of the controlled release of antigen and its intrinsic pro-inflammatory activity. Understanding how Coa-ASC16 works might have significant implications for rational vaccine design.


Assuntos
Adjuvantes Imunológicos/química , Antígenos/administração & dosagem , Ácido Ascórbico/análogos & derivados , Fator 88 de Diferenciação Mieloide/metabolismo , Vacinas/administração & dosagem , Animais , Ácido Ascórbico/química , Preparações de Ação Retardada , Humanos , Inflamassomos/efeitos dos fármacos , Inflamação/induzido quimicamente , Inflamação/patologia , Interleucinas/biossíntese , Leucócitos/efeitos dos fármacos , Cristais Líquidos , Camundongos , Camundongos Knockout , Fator 88 de Diferenciação Mieloide/genética , Ovalbumina/imunologia , Receptor Toll-Like 9/biossíntese , Receptor Toll-Like 9/genética , Receptores Toll-Like/biossíntese
11.
Toxicology ; 318: 13-21, 2014 Apr 06.
Artigo em Inglês | MEDLINE | ID: mdl-24561306

RESUMO

Sepsis remains the most important cause of acute kidney injury (AKI) in critically ill patients and is an independent predictor of poor outcome. The administration of lipopolysaccharide (LPS) to animals reproduces most of the clinical features of sepsis, including AKI, a condition associated with renal cellular dysfunction and apoptosis. Erythropoietin (EPO) is a well known cytoprotective multifunctional hormone, which exerts anti-inflammatory, anti-oxidant, anti-apoptotic and angiogenic effects in several tissues. The aim of this study was to evaluate the underlying mechanisms of EPO renoprotection through the expression of the EPO receptor (EPO-R) and the modulation of the intrinsic apoptotic pathway in LPS-induced AKI. Male inbred Balb/c mice were divided in four experimental groups: Control, LPS (8 mg/kg i.p.), EPO (3000 IU sc) and LPS+EPO. Assessment of renal function, histological examination, TUNEL in situ assay, immunohistochemistry and Western blottings of caspase-3, Bax, Bcl-xL, EPO-R and Cytochrome c were performed at 24h post treatment. LPS+EPO treatment significantly improved renal function and ameliorated histopathological injury when compared to the LPS treated group. Results showed that EPO treatment attenuates renal tubular apoptosis through: (a) the overexpression of EPO-R in tubular interstitial cells, (b) the reduction of Bax/Bcl-xL ratio, (c) the inhibition Cytochrome c release into the cytosol and (d) the decrease of the active caspase-3 expression. This study suggests that EPO exerts renoprotection on an experimental model of LPS-induced AKI. EPO induced renoprotection involves an anti-apoptotic effect through the expression of EPO-R and the regulation of the mitochondrial apoptotic pathway.


Assuntos
Injúria Renal Aguda/tratamento farmacológico , Injúria Renal Aguda/fisiopatologia , Apoptose/fisiologia , Crioprotetores/farmacologia , Eritropoetina/farmacologia , Mitocôndrias/metabolismo , Receptores da Eritropoetina/metabolismo , Injúria Renal Aguda/induzido quimicamente , Animais , Apoptose/efeitos dos fármacos , Modelos Animais de Doenças , Humanos , Rim/metabolismo , Lipopolissacarídeos , Masculino , Camundongos , Camundongos Endogâmicos BALB C
12.
Cell Biol Toxicol ; 24(5): 411-22, 2008 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-18266059

RESUMO

Apoptosis is a highly regulated and programmed cell breakdown process characterized by numerous changes. It was reported as the major mechanism of anticancer drug-induced cells death. Unfortunately, many of these drugs are non-specific and cause severe side effects. The effects of 5-fluorouracil (5-FU) on the apoptotic events in normal murine thymus were evaluated using an in vivo model. A single dose of 5-FU (150 mg/kg ip) was injected to CF-1 mice. A multiparametric analysis of thymic weight, cellularity, viability, architectural organization, apoptosis, DNA fragmentation, and the expression of several apoptotic proteins was evaluated in 10 days time-course study post-5-FU dosing. Total organ weights, thymocyte counts, and cell viabilities diminished drastically from the second day. The thymus architecture assessed through electron scanning microscopy revealed deep alterations and the lost of cell-cell contact between the first and the third days. DNA fragmentation and apoptotic indexes (May Grünwald Giemsa staining, double fluorescent dyes, and TdT-mediated dUTP nick-end labeling assay) revealed that cell death was maximal on the second day (three times over control). Furthermore, the pro-apoptotic proteins FAS and Bax were strongly up-regulated during the first 2 days. The aforementioned morphological and biochemical changes were also accompanied within the same period by caspase 3 activation. This study revealed that in vivo apoptosis in normal thymus after 5-FU administration is related to FAS, Bax, and Caspase 3 co-expressions under the current experimental conditions, these findings, therefore, contribute to a new insight into the molecular mechanisms involved during 5-FU administration upon the thymus and the possible events committed in the lymphophenia associated with chemotherapy.


Assuntos
Apoptose , Caspase 3/metabolismo , Fluoruracila/farmacologia , Timo/citologia , Proteína X Associada a bcl-2/metabolismo , Receptor fas/metabolismo , Animais , Antimetabólitos Antineoplásicos/farmacologia , Antineoplásicos/farmacologia , Dano ao DNA , Fragmentação do DNA , Feminino , Camundongos , Microscopia Eletrônica de Varredura , Modelos Biológicos , Timo/efeitos dos fármacos , Timo/metabolismo
13.
Medicina (B Aires) ; 64(6): 509-17, 2004.
Artigo em Inglês | MEDLINE | ID: mdl-15637828

RESUMO

Due to variability of venom components from the same species of snakes that inhabit different regions, particular properties of the venom of Crotalus durissus terrificus that inhabits the North-East of Argentina were studied. Gyroxin, a thrombin-like enzyme, was isolated from this venom by gel filtration and affinity chromatography, it was found to be homogeneous according to SDS-PAGE, with a molecular weight of 33 kDa. "Gyroxin syndrome" in mice was tested and it showed changes in the animal behavior, confirming that the isolated thrombin-like enzyme is gyroxin. Effects of this enzyme and the crude venom on mice plasmatic fibrinogen levels were determined. The mice plasma fibrinogen decreased rapidly until incoagulability during the first hour after thrombin-like enzyme injection, then reaching its normal level 10 hours after injection; whereas crude venom resulted in a 60% decrease of the mice plasma fibrinogen, reaching its normal level after the same period of time. After 1 hour of gyroxin inoculation, intravascular coagulation was observed in histological cuttings of lung, cardiac muscle and liver. The isolated enzyme showed strong hydrolyzing activity on fibrinogen and fibrin in vitro, whereas the crude venom exhibited weak hydrolyzing activity on both substrates. It is probable that this very low activity is due to the low percentage of the enzyme in the crude venom. Decreasing of plasmatic fibrinogen levels may be due to either the coagulant or hydrolyzing actions of the enzyme.


Assuntos
Venenos de Crotalídeos/enzimologia , Crotalus , Fibrinogênio/metabolismo , Trombina/metabolismo , Animais , Argentina , Coagulantes/farmacologia , Venenos de Crotalídeos/isolamento & purificação , Venenos de Crotalídeos/metabolismo , Venenos de Crotalídeos/farmacologia , Feminino , Fígado/patologia , Pulmão/patologia , Masculino , Camundongos
14.
Acta physiol. pharmacol. latinoam ; 39(2): 133-44, 1989. tab
Artigo em Inglês | LILACS | ID: lil-76787

RESUMO

Se evaluó la aparición de factores séricos capaces de estimular la proliferación de progenitores eritroides mamíferos. Sueron anémicos y normales de ambos e jemplares, fraccionados por tratamiento alcohólico, se ensayaron por el método del ratón post-hipóxico, no detectándose incorporación de 59Fe. Al ser ensayados en cultivos semisólidos de médula ósea murina a diferentes tiempos de incubación (colonias CFU-E y BFU-E), el suero anémico aviario mostró alta actividad estimulatória, mientras que el suero anémico anfibio resultó incapaz de incrementar la proliferación eritroide. La muestra aviaria parcialmente purificada por tratamiento alcohólico fue cromatografiada en Sephadex G-150 revelando tres entidades moleculares respondables de la actividad biológica in vitro, con pesos moleculares aparentes de 29, 14 y 10 KD respectivamente. Los factores séricos aviarios estimulantes de la línea eritroide fueron sometidos a diversos tratamientos físico-químicos y luego se evaluó la conservación de su actividad biológica. Todos ellos resultaron termoestables, sensibles al tratamiento con neuraminideasa, mientras que el ditiotreitol provocó la pérdida de la actividad biológica de las proteínas de bajo peso molecular. Estos resultados sugieren, al menos bajo estas condiciones experimentales, la presencia de factores análogos estimulantes del crecimiento eritroideo entre amniotas homeotermos


Assuntos
Camundongos , Animais , Masculino , Feminino , Sangue , Medula Óssea/citologia , Bufonidae , Fatores Estimuladores de Colônias/sangue , Células-Tronco Hematopoéticas/efeitos dos fármacos , Aves Domésticas
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA