P2X7 receptor antagonist improves gastrointestinal disorders in spontaneously hypertensive rats

The purinergic system participates in the control of blood pressure. Hypertension promotes the occurrence of gastrointestinal disorders such as intestinal inflammation and gastric emptying delay. This study aimed i) to investigate the participation of the P2X7 receptor blocker Brilliant Blue G (BBG) on gastric emptying of solids and changes in oxidative stress in the gastric fundus, duodenum, and colon of spontaneously hypertensive rats (SHR) and ii) to study the putative relationship of this effect with the renin-angiotensin system. Rats were divided into five groups: Control, SHR, SHR+BBG, SHR+BBG+ATP, and SHR+BBG+ANG II. In the gastrointestinal tract, we assessed gastric emptying (GE) and oxidative stress markers (NOx, MPO, GSH, SOD). We observed a decrease in the GE rate (P<0.05) in SHR vs control rats (21.8±2.0% vs 42.8±3.5%). The decrease in GE was returned (P<0.05) to control levels by BBG in SHR rats (21.8±2.0% vs 41.6±3.2%). Co-administration of ATP or ANG II together with BBG bypassed the effect of the P2X7 antagonist on GE in SHR (P<0.05) (21.9±5.0% vs 25.6±3.0% vs 41.6±3.2%). The MPO activity increased (P<0.05) in the gastric fundus of SHR compared to control rats (6.12±2.26 vs 0.077±0.02 UMPO/mg tissue); this effect was prevented (P<0.05) by BBG (0.55±0.15 vs 6.12±2.26 UMPO/mg tissue). Data demonstrated that blockage of P2X7 receptors with BBG can improve the GE delay and oxidative stress biomarkers in SHR animals. This preventive effect of BBG on GE delay was abrogated by ANG II and ATP, thus prompting crosstalk between renin-angiotensin and the purinergic signaling systems underlying this phenomenon.

Valuation of angiogenesis in bovine xenografts implanted in intracorporal sites of rabbits as models of in-vivo bioreactors / Avaliação da angiogênese em xenoenxertos bovinos implantados em sítios intracorpóreos de coelhos como modelos de biorreatores in vivo

The aim of this study was to evaluate neovascularization of bovine xenografts implanted in intracorporeal sites of rabbits (bioreactors). 30 rabbits were used, divided into 6 groups, according to the evaluation time (7, 15, 30, 45, and 60 days); each animal received xenogenic implants in 3 different intracorporeal sites (A1 - omentum bag; A2 - intermuscular space of quadriceps femoris; A3 - subperiosteal of ilium bone). Histological assessments graded the presence of angiogenesis, the number of inflammatory cells, newly formed bone tissue, and the presence of giant cells. Histological analyses showed intense angiogenesis in all implanted xenografts. Presence of inflammatory infiltrate and giant cells at the A1 implant site and presence of bone neoformation at the A3 implant site were noted. Degeneration of implants and formation of a fibrous capsule were noted. When comparing the interaction of the site with the days of evaluation, statistical analysis showed a significant difference (p≤0.05) in any time of neovascularization analysis. The vascular endothelial growth factor (VEGF) and inflammatory cells of the omentum in its structure, may have contributed to the greater presence of neovessels and inflammatory cells, a fact that may indicate functionality as a possible bone substitute.(AU)

O objetivo deste estudo foi avaliar a neovascularização de xenoenxertos bovinos implantados em sítios intracorpóreos de coelhos (biorreatores). Foram utilizados 30 coelhos, os quais foram divididos em seis grupos, de acordo com o tempo de avaliação (sete, 15, 30, 45 e 60 dias); cada animal recebeu implantes xenogênicos em três diferentes sítios intracorpóreos (A1 - bolsa de omento; A2 - espaço intermuscular do quadríceps femoral; A3 - subperiosteal do osso ílio). Avaliações histológicas classificaram a presença de angiogênese, o número de células inflamatórias, de tecido ósseo neoformado e a presença de células gigantes. As análises histológicas mostraram intensa angiogênese em todos os xenoenxertos implantados. Observou-se presença de infiltrado inflamatório e células gigantes no local do implante A1 e presença de neoformação óssea no local do implante A3. Ao mesmo tempo, a degeneração dos implantes e a formação de uma cápsula fibrosa foram observadas. Ao comparar a interação do local com os dias de avaliação, a análise estatística mostrou diferença significativa (P≤0,05) em qualquer momento da análise de neovascularização. O fator de crescimento endotelial vascular (VEGF) e as células inflamatórias do omento em sua estrutura podem ter contribuído para a maior presença de neovasos e células inflamatórias, fato que pode indicar funcionalidade como possível substituto ósseo.(AU)

Alanyl-glutamine protects the intestinal barrier function in trained rats against the impact of acute exhaustive exercise

Strenuous exercise triggers deleterious effects on the intestinal epithelium, but their mechanisms are still uncertain. Here, we investigated whether a prolonged training and an additional exhaustive training protocol alter intestinal permeability and the putative effect of alanyl-glutamine (AG) pretreatment in this condition. Rats were allocated into 5 different groups: 1) sedentary; 2 and 3) trained (50 min per day, 5 days per week for 12 weeks) with or without 6 weeks oral (1.5 g/kg) AG supplementation; 4 and 5) trained and subjected to an additional exhaustive test protocol with or without oral AG supplementation. Venous blood samples were collected to determine gasometrical indices at the end of the 12-week protocol or after exhaustive test. Lactate and glucose levels were determined before, during, and after the exhaustive test. Ileum tissue collected after all experimental procedures was used for gene expression analysis of Zonula occludens 1 (ZO-1), occludin, claudin-2, and oligopeptide transporter 1 (PepT-1). Intestinal permeability was assessed by urinary lactulose/mannitol test collected after the 12-week protocol or the exhaustive test. The exhaustive test decreased pH and base excess and increased pCO2. Training sessions delayed exhaustion time and reduced the changes in blood glucose and lactate levels. Trained rats exhibited upregulation of PEPT-1, ZO-1, and occludin mRNA, which were partially protected by AG. Exhaustive exercise induced intestinal paracellular leakage associated with the upregulation of claudin-2, a phenomenon protected by AG treatment. Thus, AG partially prevented intestinal training adaptations but also blocked paracellular leakage during exhaustive exercise involving claudin-2 and occludin gene expression.

The E3 ligase MuRF2 plays a key role in the functional capacity of skeletal muscle fibroblasts

Fibroblasts are a highly heterogeneous population of cells, being found in a large number of different tissues. These cells produce the extracellular matrix, which is essential to preserve structural integrity of connective tissues. Fibroblasts are frequently engaged in migration and remodeling, exerting traction forces in the extracellular matrix, which is crucial for matrix deposition and wound healing. In addition, previous studies performed on primary myoblasts suggest that the E3 ligase MuRF2 might function as a cytoskeleton adaptor. Here, we hypothesized that MuRF2 also plays a functional role in skeletal muscle fibroblasts. We found that skeletal muscle fibroblasts express MuRF2 and its siRNA knock-down promoted decreased fibroblast migration, cell border accumulation of polymerized actin, and down-regulation of the phospho-Akt expression. Our results indicated that MuRF2 was necessary to maintain the actin cytoskeleton functionality in skeletal muscle fibroblasts via Akt activity and exerted an important role in extracellular matrix remodeling in the skeletal muscle tissue.

Acute exercise inhibits gastric emptying of liquids in rats: influence of the NO-cGMP pathway

We previously found that acute exercise inhibited the gastric emptying of liquid in awake rats by causing an acid-base imbalance. In the present study, we investigated the involvement of the nitric oxide-cyclic guanosine monophosphate (NO-cGMP) pathway, vasoactive intestinal peptide (VIP), and corticotropin-releasing factor (CRF) peptide in this phenomenon. Male rats were divided into exercise or sedentary group and were subjected to a 15-min swim session against a load (2.5 or 5% b.w.). The rate of gastric emptying was evaluated after 5, 10, or 20 min postprandially. Separate groups of rats were treated with vehicle (0.9% NaCl, 0.1 mL/100 g, ip) or one of the following agents: atropine (1.0 mg/kg, ip), the NO non-selective inhibitor Nω-nitro-L-arginine methyl ester hydrochloride (L-NAME; 10.0 mg/kg, ip), or the selective cGMP inhibitor 1H-(1,2,4)oxadiazole[4,3-a]quinoxalin-1-one (ODQ; 5.0 mg/kg, ip), the i-NOS non-specific inhibitor (aminoguanidine; 10.0 mg/kg, ip), the corticotropin-releasing factor receptor antagonist (astressin; 100 µg/kg, ip), or the vasoactive intestinal peptide (VIP) receptor antagonist Lys1, Pro2,5, Arg3,4, Tyr6 (100 µg/kg, ip). Compared to sedentary rats, both the 2.5 and 5% exercise groups exhibited higher (P<0.05) values of blood lactate and fractional gastric dye recovery. Corticosterone and NO levels increased (P<0.05) in the 5% exercised rats. Pretreatment with astressin, VIP antagonist, atropine, L-NAME, and ODQ prevented the increase in gastric retention caused by exercise in rats. Acute exercise increased gastric retention, a phenomenon that appears to be mediated by the NO-cGMP pathway, CRF, and VIP receptors.

Desempenho e características de carcaça de três genótipos comerciais de frangos de corte alimentados com diferentes dietas / Performance and carcass traits of three commercial broiler genotypes fed different diets

Este estudo teve como objetivo avaliar o desempenho e as características de carcaça de frangos de corte de três genótipos comerciais do nascimento aos 35 dias de idade. Utilizou-se um total de 2.970 pintos de três genótipos de aves comerciais (Cobb 500, Hubbard Flex e Ross 308). Os programas nutricionais foram dieta basal, dieta com 10% mais e 10% menos de aminoácidos do que a dieta basal. As aves foram distribuídas em delineamento inteiramente ao acaso, em esquema fatorial 3x3x2 (genótipo x dieta x sexo), com cinco repetições e 33 aves por unidade experimental. Conversão alimentar, ganho de peso diário, ingestão da dieta e peso corporal aos 35 dias de idade foram registrados. Duas aves de cada unidade experimental foram amostradas e abatidas aos 35 dias de idade para avaliar as seguintes características de carcaça: peso corporal no momento do abate, peso da carcaça e rendimento, e peso e rendimento dos cortes (peito, pernas e asas). Houve uma interação significativa entre o genótipo e sexo para GPD e PC35. Os machos apresentaram melhores desempenhos e características de carcaças do que as fêmeas.(AU)

This study aimed to evaluate performance and carcass traits of three commercial broiler genotypes from hatch to 35 days of age. A total of 2,970 sexed one day old chicks of three commercial broiler genotypes (Cobb 500, Hubbard Flex and Ross 308) were used. The nutritional programs were basal diet, diet with 10% more and 10% less amino acids than the basal diets. Birds were distributed in a completely randomized experimental design in a 3x3x2 (genotype x diet x sex) factorial scheme, with five replicates and 33 birds per experimental unit. Feed conversion, daily weight gain, diet intake and body weight at 35 days of age were recorded. Two birds from each experimental unit were sampled and slaughtered at 35 days of age to evaluate the following carcass traits: slaughter body weight, carcass weight and yield, and main cuts (breast, legs and wings) weight and yield. There was a significant interaction between genotype and sex for ADG and BW35. Males fed basal diets presented higher performance and carcass traits in comparison to females.(AU)

Seleção e classificação multivariada de modelos não lineares para frangos de corte / Selection and classification of multivariate nonlinear models for broilers

Objetivou-se com este estudo utilizar a técnica de análise de agrupamento para classificar modelos de regressão não lineares usados para descrever a curva de crescimento de frangos de corte, levando em consideração os resultados de diferentes avaliadores de qualidade de ajuste. Para tanto, utilizaram-se dados de peso corporal e idade dos seguintes grupos genéticos de frangos de corte: Cobb500, Hubbard Flex e Ross308, de ambos os sexos, constituindo, assim, seis classes. Foram ajustados 10 modelos não lineares, cuja qualidade de ajuste foi medida pelo coeficiente de determinação ajustado, pelos critérios de informação de Akaike e bayesiano, pelo quadrado médio do erro e pelo índice assintótico. A análise de agrupamento indicou os modelos logístico, Michaelis-Menten, Michaelis-Menten modificado e von Bertalanffy como os mais adequados à descrição das curvas de crescimento das seis classes estudadas.

The aim of this study was to classify non-linear models used to describe the growth curve of broilers using the cluster analysis technique, taking into account the results of different measures of quality adjustment regression. For this purpose, we used data of body weight and age the following genetic groups of broilers: Cobb500, Hubbard Flex and Ross308, of both sexes, thus constituting six classes. Ten non-linear models were fitted, the quality of fit was measured by the adjusted coefficient of determination, Akaike information criteria and Bayesian, mean square error and index asymptotic. Cluster analysis indicated the Logistico, Michaelis Menten, Michaelis Menten Modificado and von Bertalanffy models as the most appropriate description of the growth curves for the six classes studied.

Divergência genética entre genótipos de frangos tipo caipira / Genetic divergence between genotypes of alternative strain of broiler chickens

Objetivou-se com este trabalho verificar a divergência genética entre sete genótipos de frangos tipo caipira da linhagem Redbro utilizando as características de desempenho por meio de técnicas de análise multivariada. Foram utilizados 840 pintos de um dia, machos, distribuídos em delineamento inteiramente ao acaso, dos seguintes genótipos: Caboclo, Carijó, Colorpak, Gigante Negro, Pesadão Vermelho, Pescoço Pelado e Tricolor. Após a consistência dos dados, foram avaliadas as seguintes variáveis: ganho em peso médio diário, consumo de ração médio diário e conversão alimentar, para os períodos: 1 a 28, 1 a 56, 1 a 70 e 1 a 84 dias de idade; peso corporal ao nascimento, aos 28, 56, 70 e aos 84 dias de idade. O desempenho dos genótipos foi avaliado por meio da análise de variância multivariada e da função discriminante linear de Fisher, usando os testes do maior autovalor de Roy e da união-interseção de Roy para as comparações múltiplas. O estudo da divergência genética foi feito por meio da análise por variáveis canônicas e pelo método de otimização de Tocher. Os genótipos Caboclo e Gigante Negro apresentaram médias canônicas diferentes dos demais genótipos. As duas primeiras variáveis canônicas explicaram 97,41% da variação entre os genótipos. A divergência genética entre os genótipos avaliados permitiu a formação de quatro grupos com os seguintes genótipos: grupo 1 - Colorpak; grupo 2 - Pesadão Vermelho e Pescoço Pelado; grupo 3 - Carijó e Tricolor; e grupo 4 - Caboclo e Gigante Negro.

The aim of this study was to evaluate the genetic divergence among seven genotypes of alternative strain of broiler chickens of the Redbro strain using the performance characteristics using multivariate analysis. We used 840 day old male chicks, distributed in a completely randomized design, with the following genotypes: Caboclo, Carijó, Colorpak, Gigante Negro, Pesadão Vermelho, Pescoço Pelado and Tricolor. After the consistency of the data, the following variables were analyzed: average daily gain, average daily feed intake and feed conversion for the periods: 1 to 28, 1 to 56, 1 to 70 and 1 to 84 days of age, body weight at birth, at 28, 56, 70 and at 84 days old. The performance of genotypes was assessed by multivariate analysis of variance and Fisher's linear discriminant function, using the tests of the largest eigenvalue of Roy and the Roy union-intersection for multiple comparisons. The study of genetic diversity was done by canonical variate analysis and the method of Tocher. The genotypes Caboclo and Gigante Negro had different canonical averages from the other genotypes. The first two canonical variables accounted for 97.41% of the variation among genotypes. The genetic divergence between the genotypes allowed the formation of four groups with the following genotypes: group 1 - Colorpak, group 2 - Pesadão Vermelho and Pescoço Pelado; group 3 - Carijó and Tricolor, and group 4 - Caboclo and Gigante Negro.

Cloning and molecular characterization of Trypanosoma cruzi U2, U4, U5, and U6 small nuclear RNAs

Small nuclear RNAs (snRNAs) are important factors in the functioning of eukaryotic cells that form several small complexes with proteins; these ribonucleoprotein particles (U snRNPs) have an essential role in the pre-mRNA processing, particularly in splicing, catalyzed by spliceosomes, large RNA-protein complexes composed of various snRNPs. Even though they are well defined in mammals, snRNPs are still not totally characterized in certain trypanosomatids as Trypanosoma cruzi. For this reason we subjected snRNAs (U2, U4, U5, and U6) from T. cruzi epimastigotes to molecular characterization by polymerase chain reaction (PCR) and reverse transcription-PCR. These amplified sequences were cloned, sequenced, and compared with those other of trypanosomatids. Among these snRNAs, U5 was less conserved and U6 the most conserved. Their respective secondary structures were predicted and compared with known T. brucei structures. In addition, the copy number of each snRNA in the T. cruzi genome was characterized by Southern blotting.

Physalis angulata L. antineoplasic activity, in vitro, evaluation fromit's stems and fruit capsules

Physalis angulata L. (genus Physalis; family Solanaceae) is an herbaceous specimen that grows plentifully at North, Northeast and Middleast Brazilian's regions1. Its fruits are edible, roots and epigeal parts are taken as tea or infusion, all through the world as traditional medicine. Despite of this usefulness not much scientific work has been done on it. This research carried out with plant material (stems and fruit capsules) has the main aim to find out anti-neoplasic activity. The obtained results are described in Table 1. The most significant inhibition values are those for fruit capsules fractions such as 97 percent mouse lymphoma; 93 percent Erlich carcinoma strains when was assayed with MGTS-1-2ai and MGTS-1-1ai respectively. In the course on going studies on the biological response and chemical constituents of P. angulata some fractions were obtained from stems and fruit capsules ethanolic and methanolic extracts. The extract prepared from roots of P. angulata is the most clinically used by physicians for treatment of human hepatic disorders, despite the substance responsible for the efficacy still a matter of argument.

Inibicao latente, um modelo experimental de Esquizofrenia / Latent inhibition, an experimental model of schizophrenia

Um dos modelos comportamentais mais utilizados na avaliacao de drogas antipsicoticas é o da pre-exposicao ao estímulo a ser condicionado, ou inibiçäo latente(LI). Na LI, a exposiçäo prévia a um estímulo sem consequencia retarda a aprendizagem, quando esse mesmo estímulo, numa fase posterior, é pareado com um reforçador. Neste artigo é feita, preliminarmente, uma revisäo da utilizaçäo da LI como modelo animal para avaliaçäo de drogas antipsicóticas, e de seu fundamento neuroquímico. A seguir, discutem-se os processos comportamentais implicados na pré-exposiçäo, e que explicariam o desempenho na fase de condicionamento. Duas teorias principais säo examinadas, à luz dos paradigmas respondentte e operante do comportamento: 1) a de Mackintosh, que considera que a aprendizagem deirrelevancia do estímulo ocorre quando esse näo sinaliza nenhuma mudança em um reforçador específico, e 2) a de Lubow, que defende a existencia de uma hipotética resposta de atençäo que decresceria aao longo de repetidas exposiçöes ao estímulo, o que diminuiria sua futura associabilidade quando na funçäo de estímulo condicional

Anxiogenic-like effect of acute and chronic fluoxetine on rats tested on the elevated plus-maze

The selective serotonin reuptake inhibitor fluoxetine (FLX) is widely prescribed for depression and anxiety-related disorders. On the other hand, enhanced serotonergic transmission is known to be classically related to anxiety. In this study, the effects of acute (5.0 mg/kg) and chronic (5.0 mg/kg, 22 days) FLX were investigated in both food-deprived and non-deprived rats tested in the elevated plus-maze. Significant main effects of the three factors (drug, food condition and administration regimen) were observed, but no interaction between them. The administration of either acute or chronic FLX resulted in an anxiogenic effect, as detected by a significant reduction in the percentage of time spent in the open arms and in the percentage of open arm entries. Food deprivation yielded an anxiolytic-like profile, probably related to changes in locomotor activity. The administration regimen resulted in an anxiolytic profile in chronically treated rats, as would be expected after 22 days of regular handling. The anxiogenic action of acute FLX is consistent with both its neurochemical and clinical profile. The discrepancy between the anxiogenic profile of chronic FLX and its therapeutic uses is discussed in terms of possible differences between the type of anxiety that is measured in the plus-maze and the types of human anxiety that are alleviated by fluoxetine

Aterectomia coronária rotacional por ablaçäo e a assistência de enfermagem / Nurse assistance in rotational atherectomy

As indicaçöes no tratamento de lesöes coronárias complexas foram ampliadas com o avanço técnico e tecnológico da Cardiologia Intervencionista. Dentre as técnicas desenvolvidas para superar as limitaçöes no tratamento de lesöes coronárias, a aterectomia coronária rotacional é uma delas. Cabe à enfermagem a atualizaçào constante e, por meio da sistematizaçäo da assistência, prestar os cuidados no pé, no trans e no pós-procedimento, contribuindo assim para osucesso da nova técnica e para a boa evoluçädo paciente durante a fase hospitalar.