Lead (Pb) is one of the most commonly occurring, highly persistent and widely distributed heavy metal contaminants in the environment. It has a tendency to bioaccumulate in animals and plants, and potentially, it is able to enter the human food chain where it poses a hazard to public health. Generally, conventional remediation technologies applied to decontaminate heavy metals from groundwater and soils are very costly. Hence, phytoremediation has emerged as an ecologically friendly and economically attractive technology that uses green plants to clean up heavy metal contaminated sites. However, a lack of knowledge of the biological processes associated with plant responses to Pb (e.g. Pb uptake, accumulation, translocation, and tolerance) has been a bottleneck for the application of Pb phytoremediation in the field. A model genetic system of higher plants, Arabidopsis thaliana, was selected to further examine the physiological, biochemical and molecular events occuring in plants under Pb stress. The overall aim of this project was to obtain a better understanding of plant responses to Pb contaminants in the early developmental stages of A. thaliana seedlings. This research encompassed the physiological responses of A. thaliana seedlings to Pb exposure, monitoring their antioxidative defence systems, and investigating the participation of annexin 1 in the response to Pb-mediated oxidative stress. This research also assessed the protective effect of nitric oxide on Pb-induced toxicity of A. thaliana seedlings and it isolated a putative Pb tolerant mutant from an EMS-mutagenized M2 population. A multiexperimental approach was adopted to achieve these objectives. A. thaliana seedlings were grown on modified Huang & Cunningham (1996) nutrient solution containing 0.8% (w/v) agar, with and without Pb(NO3)2, under controlled conditions. A. thaliana seedlings were insensitive to Pb during seed germination. In treatments with up to 200 μM Pb(NO₃)₂, morphological changes and inhibition of root growth were observed in the 7-d-old seedlings. A tolerance index revealed that Pb(NO₃)₂ concentration of 75 μM and higher brought about more than 50% root growth inhibition. Pb was predominantly retained in the roots. Analysis using a graphite furnace atomic absorption spectroscopy indicated that the level of Pb accumulation in A. thaliana roots was greatly dependent on the Pb(NO₃)₂ concentrations, but only a small fraction of the accumulated Pb was translocated to the shoots (18 - 43%). Transmission electron microscopy analysis showed that Pb was mainly immobilized in the cell walls and intercellular spaces. This was interpreted as a mechanism that minimizes the entry of Pb into cells and interference with cellular functions. Pb that gained entry into the cytoplasm was sequestered into the vacuoles. The toxicity of Pb in the cytosol of A. thaliana seedlings was studied by measuring the H₂O₂ and lipid hydroperoxide levels using a microplate reader. When the Pb(NO₃)₂ concentration in the growth medium was 100 μM, the 7-d-old seedlings contained 2.2-fold higher H₂O₂ and 9.6-fold higher lipid hydroperoxide than the control without Pb(NO₃)₂. This was followed by an up-regulation of the activity of antioxidative enzymes, including superoxide dismutase (SOD), catalase (CAT), glutathione reductase (GR), glutathione peroxidase (GPX), and general peroxidase (POD) by 2.1-, 3.2-, 2.3-, 1.8- and 4.6-fold, respectively, compared with the control. Pb toxicity is known to trigger oxidative stress, but A. thaliana seedlings appeared to be capable of activating cell rescue, defending themselves against harmful oxidative stress and also acclimating to Pb. Data from physiological and biochemical analysis indicate that a combination of avoidance and tolerance mechanisms exists in Pb-treated A. thaliana seedlings to maintain the essential cellular metabolism for survival. Real-time reverse-transcription polymerase chain reaction was used to show the involvement of AnnAt1 in the response of 7-d-old A. thaliana seedlings to a high threshold concentration of Pb. When the seedlings were treated with 100 μM Pb(NO₃)₂, AnnAt1 message levels were up-regulated by 2.12-fold. Pb-mediated oxidative stress may be a component of AnnAt1 gene expression. AnnAt1 potentially could be invoked to reduce the toxic effects of Pb stress by acting as ROS and/or Ca²⁺ signals, as a membrane protector, in detoxification of excessive ROS, or in sequestration of Pb. Pb stress symptoms were less evident in seedlings pre-treated with 1 mM sodium nitroprusside (SNP), a nitric oxide (NO) donor. The present study found that exogenous NO did not alter Pb transport into the plants or efflux pumping of Pb at the plasma membrane. However, NO conferred protection to 7-d-old A. thaliana seedlings primarily by acting as an antioxidant or a signal for actions to scavenge excessive ROS level. The application of exogenous NO before subjecting to 100 μM Pb(NO₃)₂ decreased H₂O₂ back to its original level, and reduced 50% lipid hydroperoxide in the Pb-treated seedlings. As a result, the antioxidative enzyme activities in Pb-exposed seedlings pre-treated with SNP were 23 - 45% lower than those without SNP pre-treatment. Less antioxidative enzyme activities were probably needed to counteract the reduced amount of Pb-induced ROS in A. thaliana seedlings. A post-germination procedure involving prolonged exposure to 150 μM Pb(NO₃)₂ was developed to screen an EMS-mutagenized M2 population of A. thaliana. Potential Pb tolerant mutants were selected based on the ability to grow with their roots penetrating into the medium and maintain purple-green leaves without wilting. A minority of the survivors appeared to go into a resting stage and they seemed to have altered transporters that prevented Pb from entering the cells. Only one putative Pb mutant (M3-1) was recovered from the rescue and set seeds. The M₄ generation of this putative Pb mutant was re-screened for phenotypic confirmation and to determine the regulation of AnnAt1. The 7-d-old putative Pb mutant seemed to display enhanced root and shoot growth in the presence of 150 μM Pb(NO₃)₂ compared to the wild-type seedlings. The transcript level of AnnAt1 in this putative Pb tolerant mutant increased by 2.19-fold when exposed to 150 μM Pb(NO₃)₂.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / A asma é uma doença inflamatória crônica caracterizada por hiper-reatividade das vias aéreas, acúmulo de eosinófilos, secreção de muco e remodelamento. No decorrer do estabelecimento do processo inflamatório, há liberação de mediadores endógenos que atuam limitando a evolução do quadro patológico e garantindo a manutenção da homeostasia (COHN, ELIAS e CHUPP, 2004). Dentre estes recebem destaque os hormônios glicocorticóides, reconhecidos por sua atividade anti-inflamatória, dependente, em parte, da geração de fatores intermediários como a proteína anexina-1 (AnxA1) (KAMAL, FLOWER e PERRETTI, 2005; PERRETTI, 2003). Neste estudo investigou-se o papel regulatório da AnxA1 e do peptídeo derivado Ac2-26 (50 - 200 g/animal) no modelo experimental de asma alérgica murina. Camundongos BALB/c (AnxA1+/+) e depletados do gene codificante para AnxA1 (AnxA1-/-) foram sensibilizados com ovoalbumina (OVA 50 g) e hidróxido de alumínio (5 mg), por via subcutânea. Após 14 dias, foi feito reforço com OVA (25 g), por via intraperitoneal, e nos dias 19, 20 e 21 foram desafiados com OVA (25 g), por via intranasal. O tratamento consistiu na administração intranasal do peptídeo Ac2-26 (50 - 200 g), 1 h antes de cada desafio. As análises foram feitas 24 h após o último desafio e incluíram: i) função pulmonar (resistência e elastância) e hiper-reatividade das vias aéreas à metacolina (3 27 mg/ml) através de pletismografia invasiva; ii) alterações morfológicas através de histologia clássica; iii) quantificação de colágeno e iv) quantificação de mediadores inflamatórios através de ELISA. Verificou-se que camundongos AnxA1-/-, quando ativamente sensibilizados e desafiados com OVA apresentaram exacerbação do quadro de hiper-reatividade das vias aéreas, assim como do número de eosinófilos no lavado broncoalveolar e no infiltrado peribrônquico, deposição de colágeno e nos níveis de IL-13 em comparação aos controles AnxA1+/+. Em paralelo, observou-se que o peptídeo Ac2-26 levou a uma redução da hiper-reatividade das vias aéreas frente à estimulação com metacolina nos animais AnxA1+/+. O peptídeo Ac2-26 reduziu o infiltrado inflamatório no parênquima pulmonar e o número de eosinófilos peribronquiolares, além da produção de muco no tecido pulmonar e da geração IL-4, IL-13, eotaxina-1 e -2. Em conjunto, nossos achados mostram que os camundongos AnxA1-/- mostraram-se mais responsivos à estimulação antigênica, o que foi indicativo de que a AnxA1 parece exercer um papel regulatório importante sobre a resposta inflamatória alérgica murina. Além disso, o efeito inibitório do peptídeo Ac2-26 sobre a resposta alérgica pulmonar foi indicativo de que este se coloca como um composto anti-inflamatório e anti-alérgico promissor para utilização na terapia da asma. / Asthma is a chronic inflammatory disease characterized by airways hyperreactivity, eosinophil accumulation, mucus secretion as well as remodeling. During the establishment of the inflammatory process, endogenous mediators are released in order limit the progression of the pathological process (COHN, ELIAS e CHUPP, 2004). Glucocorticoid hormones are considered as critical based on their potent anti-inflammatory activity, which is at least partially dependent on the release of intermediate factors such as the protein annexin-1 (KAMAL, FLOWER e PERRETTI, 2005; PERRETTI, 2003). In this study, we investigated the role of annexin-1 (AnxA1) and its derived peptide Ac2-26 (50 200 g/animal) on the experimental model of allergic asthma in mice. BALB/c (AnxA1+/+) and AnxA1 knockout mice (AnxA1-/-) were sensitized with subcutaneous injection of ovalbumin (OVA 50 g) plus aluminum hydroxide (5 mg). On day 14, animals were boosted intraperitoneally with OVA (25 g) and on days 19, 20 and 21 post-sensitization, mice were challenged intranasally with OVA (25 g). Treatment was performed by intranasal administration of Ac2-26 peptide (50 - 200 g), 1 h before each challenge. The analyses were made 24 h after the last provocation and included: i) lung function (resistance and elastance) and airways hyperreactivity to methacholine (3-27 mg/ml) by invasive plethysmography, ii) morphology by classical histological techniques; iii) collagen quantification and iv) cytokine generation evaluated by ELISA. It was noted that AnxA1-/- mice, when sensitized and challenged with OVA showed exacerbation of airways hyperreactivity, eosinophils present in the bronchoalveolar lavage and peribronchial tissue, collagen deposition and increased levels of IL-13 as compared to AnxA1+/+. In parallel, it was showed that treatment of AnxA1+/+ mice with the Ac2-26 peptide markedly inhibited airways hyperreactivity, peribronchial eosinophil accumulation, mucus production and the generation of IL-13 and eotaxin-1 and -2. Taken together our results show that AnxA1-/- mice were more responsive to antigen stimulation, which is an indicative that AnxA1 plays an important regulatory role in the murine allergic inflammatory response. In addition, the inhibitory effect of the Ac2-26 peptide on the allergic lung inflammation clearly indicated that it seems to be a promising anti-inflammatory and anti-allergic agent to be used in the asthma therapy.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / A asma é uma doença inflamatória crônica caracterizada por hiper-reatividade das vias aéreas, acúmulo de eosinófilos, secreção de muco e remodelamento. No decorrer do estabelecimento do processo inflamatório, há liberação de mediadores endógenos que atuam limitando a evolução do quadro patológico e garantindo a manutenção da homeostasia (COHN, ELIAS e CHUPP, 2004). Dentre estes recebem destaque os hormônios glicocorticóides, reconhecidos por sua atividade anti-inflamatória, dependente, em parte, da geração de fatores intermediários como a proteína anexina-1 (AnxA1) (KAMAL, FLOWER e PERRETTI, 2005; PERRETTI, 2003). Neste estudo investigou-se o papel regulatório da AnxA1 e do peptídeo derivado Ac2-26 (50 - 200 g/animal) no modelo experimental de asma alérgica murina. Camundongos BALB/c (AnxA1+/+) e depletados do gene codificante para AnxA1 (AnxA1-/-) foram sensibilizados com ovoalbumina (OVA 50 g) e hidróxido de alumínio (5 mg), por via subcutânea. Após 14 dias, foi feito reforço com OVA (25 g), por via intraperitoneal, e nos dias 19, 20 e 21 foram desafiados com OVA (25 g), por via intranasal. O tratamento consistiu na administração intranasal do peptídeo Ac2-26 (50 - 200 g), 1 h antes de cada desafio. As análises foram feitas 24 h após o último desafio e incluíram: i) função pulmonar (resistência e elastância) e hiper-reatividade das vias aéreas à metacolina (3 27 mg/ml) através de pletismografia invasiva; ii) alterações morfológicas através de histologia clássica; iii) quantificação de colágeno e iv) quantificação de mediadores inflamatórios através de ELISA. Verificou-se que camundongos AnxA1-/-, quando ativamente sensibilizados e desafiados com OVA apresentaram exacerbação do quadro de hiper-reatividade das vias aéreas, assim como do número de eosinófilos no lavado broncoalveolar e no infiltrado peribrônquico, deposição de colágeno e nos níveis de IL-13 em comparação aos controles AnxA1+/+. Em paralelo, observou-se que o peptídeo Ac2-26 levou a uma redução da hiper-reatividade das vias aéreas frente à estimulação com metacolina nos animais AnxA1+/+. O peptídeo Ac2-26 reduziu o infiltrado inflamatório no parênquima pulmonar e o número de eosinófilos peribronquiolares, além da produção de muco no tecido pulmonar e da geração IL-4, IL-13, eotaxina-1 e -2. Em conjunto, nossos achados mostram que os camundongos AnxA1-/- mostraram-se mais responsivos à estimulação antigênica, o que foi indicativo de que a AnxA1 parece exercer um papel regulatório importante sobre a resposta inflamatória alérgica murina. Além disso, o efeito inibitório do peptídeo Ac2-26 sobre a resposta alérgica pulmonar foi indicativo de que este se coloca como um composto anti-inflamatório e anti-alérgico promissor para utilização na terapia da asma. / Asthma is a chronic inflammatory disease characterized by airways hyperreactivity, eosinophil accumulation, mucus secretion as well as remodeling. During the establishment of the inflammatory process, endogenous mediators are released in order limit the progression of the pathological process (COHN, ELIAS e CHUPP, 2004). Glucocorticoid hormones are considered as critical based on their potent anti-inflammatory activity, which is at least partially dependent on the release of intermediate factors such as the protein annexin-1 (KAMAL, FLOWER e PERRETTI, 2005; PERRETTI, 2003). In this study, we investigated the role of annexin-1 (AnxA1) and its derived peptide Ac2-26 (50 200 g/animal) on the experimental model of allergic asthma in mice. BALB/c (AnxA1+/+) and AnxA1 knockout mice (AnxA1-/-) were sensitized with subcutaneous injection of ovalbumin (OVA 50 g) plus aluminum hydroxide (5 mg). On day 14, animals were boosted intraperitoneally with OVA (25 g) and on days 19, 20 and 21 post-sensitization, mice were challenged intranasally with OVA (25 g). Treatment was performed by intranasal administration of Ac2-26 peptide (50 - 200 g), 1 h before each challenge. The analyses were made 24 h after the last provocation and included: i) lung function (resistance and elastance) and airways hyperreactivity to methacholine (3-27 mg/ml) by invasive plethysmography, ii) morphology by classical histological techniques; iii) collagen quantification and iv) cytokine generation evaluated by ELISA. It was noted that AnxA1-/- mice, when sensitized and challenged with OVA showed exacerbation of airways hyperreactivity, eosinophils present in the bronchoalveolar lavage and peribronchial tissue, collagen deposition and increased levels of IL-13 as compared to AnxA1+/+. In parallel, it was showed that treatment of AnxA1+/+ mice with the Ac2-26 peptide markedly inhibited airways hyperreactivity, peribronchial eosinophil accumulation, mucus production and the generation of IL-13 and eotaxin-1 and -2. Taken together our results show that AnxA1-/- mice were more responsive to antigen stimulation, which is an indicative that AnxA1 plays an important regulatory role in the murine allergic inflammatory response. In addition, the inhibitory effect of the Ac2-26 peptide on the allergic lung inflammation clearly indicated that it seems to be a promising anti-inflammatory and anti-allergic agent to be used in the asthma therapy.

Made available in DSpace on 2014-06-11T19:26:03Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-12-17Bitstream added on 2014-06-13T20:14:35Z : No. of bitstreams: 1 jorge_yc_me_sjrp.pdf: 4700733 bytes, checksum: 1fa001424eaf0ffba4a8cdeb55c5fce5 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / No presente estudo foram investigados os níveis de expressão gênica e protéica da anexina-1 (ANXA1/AnxA1) e galectina-1 (LGALS1/Gal-1) na carcinogênese do estômago e associações com infecção pela Helicobacter pylori e o genótipo de virulência bacteriano cagA+. A análise foi realizada em 40 biópsias de mucosa gástrica com gastrite crônica (CG), 20 de câncer gástrico (GA) e 10 de mucosa normal (C), pelas técnicas de qPCR para quantificar os níveis de RNAm; imuno-histoquímica para caracterizar a expressão protéica na mucosa gástrica, e PCR para diagnóstico molecular da H. pylori e cepa cagA+. O estudo mostrou resultados inéditos quanto à expressão desses genes em gastrite crônica, ainda sem descrições na literatura. Foi demonstrada expressão relativa elevada do mRNA de ANXA1 em 80% dos casos de GA (média de 4,38 + 4,77) e em 90% dos casos de CG (média de 4,26 + 2,03), sem diferença significante entre os grupos (p = 0,33). O gene LGALS1 apresentou expressão elevada em 60% dos casos GA (média de 2,44 + 3,26) e, expressão constitutiva na CG (média de 0,43 + 3,13), mostrando, portanto, diferença significante entre os grupos (p < 0,01). A imuno-histoquímica revelou que as proteínas AnxA1 e Gal-1 não são expressas na mucosa normal. Ao contrário, durante o processo inflamatório de CG, imunomarcação citoplasmática positiva para a AnxA1 foi observada na porção basal do epitélio e estroma e, para Gal-1 a expressão foi constatada na porção apical e borda estriada do epitélio além do estroma. No adenocarcinoma tipo intestinal foi observada expressão citoplasmática em toda extensão epitelial e estroma tanto para a AnxA1 quanto para a Gal-1. Por outro lado, no tipo difuso imunomarcação positiva também foi observada no núcleo e membrana plasmática... / In this study we investigated the levels of gene and protein expression of annexin-1 (ANXA1/Anxa1) and galectin-1 (LGALS1/Gal-1) in gastric carcinogenesis and associations with Helicobacter pylori infection and bacterial virulence genotype cagA+. The analysis was performed in 40 biopsies of gastric mucosa with chronic gastritis (CG), 20 with gastric cancer (GA) and 10 of normal mucosa (C), by the techniques of qPCR to quantify mRNA levels, immunohistochemistry to characterize the protein expression in gastric mucosa, and PCR for molecular diagnosis of H. pylori cagA+ strains. This is the first study regarding the expression of these genes in chronic gastritis. High ANXA1expression levels were demonstrated in 80% of GA cases (mean 4.38 + 4.77) and in 90% of GC cases (mean 4.26 + 2.03), with no significant difference between groups (p = 0.33). High LGALS1 gene expression was found in 60% of GA cases (average 2.44 + 3.26), and constitutive expression was found in CG (mean 0.43 + 3.13), showing therefore a significant difference between groups (p <0.01). Immunohistochemistry revealed that the proteins AnxA1 and Gal-1 are not expressed in normal mucosa. In contrast, during the inflammatory process of CG, positive cytoplasmic immunostaining for AnxA1 was observed in the basal epithelium and stroma, and Gal-1 expression was detected in the apical portion and striated border of the epithelium and stroma. In intestinal-type adenocarcinoma was observed cytoplasmic expression in all epithelial and stromal extension for both AnxA1 and Gal-1. On the other hand, in diffuse-type adenocarcinoma positive immunostaining was also observed in the nucleus and plasma membrane of both proteins. Infection by H. pylori showed no association with the expression of both genes, but the genotype cagA+ is associated with about 2.5 times... (Complete abstract click electronic access below)

Orientador: Ana Elizabete Silva / Banca: Kátia Ramos Moreira Leite / Banca: Cristiane Damas Gil / Resumo: No presente estudo foram investigados os níveis de expressão gênica e protéica da anexina-1 (ANXA1/AnxA1) e galectina-1 (LGALS1/Gal-1) na carcinogênese do estômago e associações com infecção pela Helicobacter pylori e o genótipo de virulência bacteriano cagA+. A análise foi realizada em 40 biópsias de mucosa gástrica com gastrite crônica (CG), 20 de câncer gástrico (GA) e 10 de mucosa normal (C), pelas técnicas de qPCR para quantificar os níveis de RNAm; imuno-histoquímica para caracterizar a expressão protéica na mucosa gástrica, e PCR para diagnóstico molecular da H. pylori e cepa cagA+. O estudo mostrou resultados inéditos quanto à expressão desses genes em gastrite crônica, ainda sem descrições na literatura. Foi demonstrada expressão relativa elevada do mRNA de ANXA1 em 80% dos casos de GA (média de 4,38 + 4,77) e em 90% dos casos de CG (média de 4,26 + 2,03), sem diferença significante entre os grupos (p = 0,33). O gene LGALS1 apresentou expressão elevada em 60% dos casos GA (média de 2,44 + 3,26) e, expressão constitutiva na CG (média de 0,43 + 3,13), mostrando, portanto, diferença significante entre os grupos (p < 0,01). A imuno-histoquímica revelou que as proteínas AnxA1 e Gal-1 não são expressas na mucosa normal. Ao contrário, durante o processo inflamatório de CG, imunomarcação citoplasmática positiva para a AnxA1 foi observada na porção basal do epitélio e estroma e, para Gal-1 a expressão foi constatada na porção apical e borda estriada do epitélio além do estroma. No adenocarcinoma tipo intestinal foi observada expressão citoplasmática em toda extensão epitelial e estroma tanto para a AnxA1 quanto para a Gal-1. Por outro lado, no tipo difuso imunomarcação positiva também foi observada no núcleo e membrana plasmática... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: In this study we investigated the levels of gene and protein expression of annexin-1 (ANXA1/Anxa1) and galectin-1 (LGALS1/Gal-1) in gastric carcinogenesis and associations with Helicobacter pylori infection and bacterial virulence genotype cagA+. The analysis was performed in 40 biopsies of gastric mucosa with chronic gastritis (CG), 20 with gastric cancer (GA) and 10 of normal mucosa (C), by the techniques of qPCR to quantify mRNA levels, immunohistochemistry to characterize the protein expression in gastric mucosa, and PCR for molecular diagnosis of H. pylori cagA+ strains. This is the first study regarding the expression of these genes in chronic gastritis. High ANXA1expression levels were demonstrated in 80% of GA cases (mean 4.38 + 4.77) and in 90% of GC cases (mean 4.26 + 2.03), with no significant difference between groups (p = 0.33). High LGALS1 gene expression was found in 60% of GA cases (average 2.44 + 3.26), and constitutive expression was found in CG (mean 0.43 + 3.13), showing therefore a significant difference between groups (p <0.01). Immunohistochemistry revealed that the proteins AnxA1 and Gal-1 are not expressed in normal mucosa. In contrast, during the inflammatory process of CG, positive cytoplasmic immunostaining for AnxA1 was observed in the basal epithelium and stroma, and Gal-1 expression was detected in the apical portion and striated border of the epithelium and stroma. In intestinal-type adenocarcinoma was observed cytoplasmic expression in all epithelial and stromal extension for both AnxA1 and Gal-1. On the other hand, in diffuse-type adenocarcinoma positive immunostaining was also observed in the nucleus and plasma membrane of both proteins. Infection by H. pylori showed no association with the expression of both genes, but the genotype cagA+ is associated with about 2.5 times... (Complete abstract click electronic access below) / Mestre

Made available in DSpace on 2016-01-26T12:51:24Z (GMT). No. of bitstreams: 1 fernandonestor_tese.pdf: 1042593 bytes, checksum: af0a555c2adb2f553fd7214a6ca2774b (MD5) Previous issue date: 2006-03-14 / The aim of the present study was to investigate the effects of the use of the anti-inflammatory protein annexin 1 (Anx-A1), which is found in most cells. It is characterized by its ability in binding to calcium and phospholipids, conferring protection against the initial effects of ischemia-reperfusion injury. Right nephrectomy was performed on 48 adult males Wistar rat, with sizes ranging between 250-300 g, maintained on a diet normosodic , normoprotein and with water ad libitum. The animals was divided into 3 groups: Annexin-1/Ischemia (Anx-A1-I/R) (n=16), vehicle (PBS40)-Ischemia (Vehicle-I/R) (n=16) and Sham Group (n=16). The endovenous administration of Anx-A1 was made 30 minutes before ischemia of the left renal artery. The animals of each group were divided and studied at 2 and 7 days post-reperfusion, in respect to the glomerular, tubular and renal structure functions. The results showed that there was a reduction in the glomerular filtration rate (GFR) in the Vehicle-I/R Groups at 2 and 7 days post-reperfusion (0.42 ± 0.02 mL/min-100g and 0.48 ± 0.05 mL/min-100g, respectively). There was a significantly greater filtration rate in the Anx-A1-I/R Groups compared to the Vehicle-I/R Groups (0.86 ± 0.05 mL/min-100g and 0.73 ± 0.04 mL/min-100g, respectively). A significant difference between the Anx-A1-I/R and Sham Groups (p-value < 0.01) was also observed (7days). The fractional sodium excretion (FeNa) was significantly higher in the Vehicle-I/R Groups when compared to the Anx-A1-I/R and Sham Groups on the 2nd and 7th post-perfusion days. On the 2nd day of the study, the fractional sodium excretion was 0.17 ± 0.01% for the Anx-A1-I/R, 0.42 ± 0.03% for the Vehicle-I/R and 0.21 ± 0.01% for the Sham groups (p-value < 0.001). On the 7th day, the values were 0.27 ± 0.03%, 0.52 ± 0.03% and 0.29 ± 0.01%, respectively (p-value < 0.001). The potassium excretion fraction (FeK) on the 2nd and 7th post-perfusion days did not differentiate between the Anx-A1-I/R and Sham Groups, but it was significantly higher in the Vehicle-I/R Groups. The urinary-plasmatic osmolality ratio (U/Posm) showed a significant reduction in the Vehicle-I/R Groups after 2 and 7 days when compared with the Anx-A1-I/R and Sham Groups. A histopathologic evaluation of renal cortex samples, taken on the 2nd and 7th post-perfusion days, revealed a significant increase in the intravascular and transmigrated neutrophils in ischemic areas of the Vehicle-I/R Groups. Additionally, high rates of transmigrated neutrophils were identified in the ischemia-reperfusion areas of samples of renal medulla from the Vehicle-I/R Group taken on the 2nd and 7th days. There was a significant reduction of the neutrophil transmigration in samples of renal medulla on the 2nd and 7th post-perfusion days in the Anx-A1-I/R Groups, as well as a lower intravascular neutrophil rate. On the 2nd and 7th post-perfusion days, the Sham Group presented with structures of distal and proximal convoluted tubules and well-preserved brush-border structures in the renal cortex and medulla samples as seen by light microscopy. Similar results were evidenced in the Anx-A1-I/R Groups with preserved structures in the tubules, basal membrane and glomeruli. In the Vehicle-IR Groups, numerous monocytes, cellular debris inside proximal convoluted tubules, dilated capillaries and alterations in the basal membrane structure were seen. These results suggest that the administration of annexin-1 thirty minutes before renal ischemia in rat , prevents the transmigration of neutrophils and confers protection against the initial effects of ischemia-reperfusion injury, as well as providing protection to the glomerular, tubular and renal structure functions. / O presente estudo objetivou investigar os efeitos do uso da anexina 1 (Anx-A1), considerada proteína antiinflamatória e que está presente na maioria das células. Caracteriza-se pela sua habilidade em ligar-se ao cálcio e fosfolipídeos, conferindo proteção contra os efeitos iniciais da lesão por isquemia e reperfusão. Realizou-se nefrectomia à direita em 48 ratos (Wistar-adultos-machos), pesando entre 250-300 gramas, mantidos com dieta normosódica , normoprotéica e água ad libitum. Os animais foram divididos em 3 grupos: Anexina 1-Isquemia (Anx-A1-I/R) (n=16), Veículo(PBS-40)-Isquemia (Veic-I/R) (n=16) e grupo Sham (n=16). A administração de anexina1 endovenosa foi realizada 30 minutos antes do clampeamento da artéria renal esquerda. Após reperfusão, os animais de cada grupo foram divididos e estudados com 2 e 7 dias, quanto às funções glomerulares , tubulares e à estrutura renal. Os resultados mostraram que houve redução da taxa de filtração glomerular (RFG) nos grupos veículo-I/R com 2 e 7 dias de experimento (0,42 ± 0,02 ml-min-100g e 0,48 ± 0,05 ml-min-100g, respectivamente) e verificamos aumento significativo da taxa de filtração glomerular nos grupos Anx-A1-I/R comparados aos grupos veículo-I/R (0,86 ± 0,05ml-min-100g e 0,73 ± 0,04ml-min-100g, respectivamente). Observou-se diferença significativa entre os grupos Anx-A1-I/R e Sham com 7 dias (p<0,01). A excreção fracional de sódio (FeNa) apresentou-se significantemente aumentada nos grupos veículo-I/R, comparada aos grupos Anx-A1-I/R e Sham nos 2º e 7º dias de experimento; apresentando assim no 2º dia de estudo,Anx-A1-I/R (0,17 ± 0,01%), Veic-I/R (0,42 ± 0,03%) e Sham (0,21 ± 0,01%) (p<0,001); e no 7º dia, Anx-A1-I/R (0,27 ± 0,03%), Veic-I/R (0,52 ± 0,03%) e Sham (0,29 ± 0,01%) (p<0,001). A fração de excreção de potássio (FeK) com 2 e 7 dias de experimento não diferiram entre os grupos Anx-A1-I/R e Sham, mas a FeK aumentou significativamente nos grupos Veic-IR. A razão das osmolalidades urinário-plasmáticas (U/Posm) mostraram uma redução importante nos grupos Veic-I/R em experimentos com 2 e 7 dias, comparados aos grupos Anx-A1-I/R e Sham. A avaliação histopatológica revelou aumento significativo de neutrófilos intravasculares e transmigrados, em áreas isquêmicas dos grupos Veic-I/R, de amostras avaliadas da porção do córtex renal com 2 e 7 dias. Verificaram-se altas taxas de transmigração de neutrófilos nas áreas de isquemia-reperfusão nos grupos Veic-I/R com 2 e 7 dias, em amostras avaliadas de medula renal. Houve significativa redução do extravasamento de neutrófilos em análise quantitativa, nas amostras de medula renal com 2 e 7 dias de estudo, nos grupos anexina 1-I/R, bem como menor taxa de neutrófilos no espaço intravascular. À microscopia de luz, verificou-se que, em amostras de córtex e medula renal, com 2 e 7 dias, o grupo Sham apresentou estruturas dos túbulos contorcidos proximais, distais e borda em escova bem preservados. Notou-se resultados semelhantes nos grupos de anexina1-I/R, com estruturas preservadas nos túbulos, membrana basal e glomérulos. Nos grupos Veic-I/R, verificou-se a presença de debris celulares no interior de túbulos contorcidos proximais, capilares dilatados e alterações na estrutura da membrana basal. Estes resultados sugerem que a administração da anexina1, trinta minutos antes da isquemia renal em ratos, previne a transmigração de neutrófilos e confere proteção contra os efeitos iniciais da lesão por isquemia e reperfusão, bem como proteção das funções glomerulares, tubulares e da estrutura renal.