Protective effect of prior physical conditioning on relaxing response of corpus cavernosum from rats made hypertensive by nitric oxide inhibition

The aim of this work was to evaluate the influence of run training on the responsiveness of corpus cavernosum (CC) from rats made hypertensive by treatment with nitric oxide (NO) synthesis inhibitor. Wistar rats were divided into sedentary control (C-SD), exercise training (C-TR), N(omega)-nitro-L-arginine methyl ester (L-NAME) sedentary (LN-SD) and L-NAME trained (LN-TR) groups. The run training program consisted in 8 weeks in a treadmill, 5 days/week, each session lasted 60 min. L-NAME treatment (2 and 10mg/rat/day) started after 4 weeks of prior physical conditioning and lasted 4 weeks. Concentration-response curves were obtained for acetylcholine (ACh), sodium nitroprusside (SNP), sildenafil and BAY 41-2272. The effect of electrical field stimulation (EFS) on the relaxations responses of CC was evaluated. Run training prevented the arterial hypertension induced by L-NAME treatment (LN-SD: 135+/-2 and 141+/-2 mm Hg for both doses of L-NAME) compared to LN-SD groups (154+/-1 and 175+/-2 mm Hg, for 2 and 10 mg of L-NAME, respectively). Run training produced an increase in the maximal responses (E(max)) of CC for ACh (C-SD: 47+/-3; C-TR: 5271; and LN-TR: 53+/-3%) and SNP (C-SD: 8971; C-TR: 9871; and LN-TR: 95+/-1%). Both potency and E(max) for ACh were reduced in a dose of 10 mg of L-NAME, and run training restored the reduction of E(max) for ACh. No changes were found for BAY 41-2271 and sildenafil. Relaxing responses to EFS was reduced by L-NAME treatment that was restored by prior physical conditioning. In conclusion, our study shows a beneficial effect of prior physical conditioning on the impaired CC relaxing responses in rats made hypertensive by chronic NO blockade.

Atypical beta-adrenoceptor subtypes mediate relaxations of rabbit corpus cavernosum

This study was performed to characterize the beta-adrenoceptor population in rabbit isolated corpus cavernosum (RbCC) by using nonselective and selective beta-adrenoceptor agonists and antagonists in functional assays. Metaproterenol, ritodrine, fenoterol, and 8-hydroxy-5-[(1R)-1-hydroxy-2-[N-[(1R)-2-(rho-methoxy-phenyl)1-methylethyl] amino] ethyl] carbostyril (TA 2005) (3-100 nmol each) dose dependently relaxed the RbCC preparations. These relaxations were markedly reduced by N-omega-nitro-L-arginine methyl ester (L-NAME; 10 muM) and 1H-[1,2,4]-oxadiazolo-[4,3,-a]quinoxalin-1-one (ODQ) (10 muM), whereas the adenylyl cyclase inhibitor SQ 22,536 [9-(2-tetrahydrofuryl)adenine] (10 muM) had no effect. In contrast, neither L-NAME nor ODQ affected the isoproterenol-induced RbCC relaxations, but SQ 22,536 abolished this response. Sildenafil (1 muM) significantly potentiated the relaxations induced by beta(2)-agonists without affecting the isoproterenol-evoked relaxations. Rolipram (10 muM) enhanced the relaxations elicited by isoproterenol but had no effect on those induced by the selective beta(2) agonists. Propranolol and (+/-)-1-[2,3-(dihydro-7-methyl-1H-inden-4-yl)oxy]-3-[(1-methylethyl)amino]-2-butanolhydrochloride (ICI 118,551) determined a rightward shift in the concentration-response curves to isoproterenol in a noncompetitive manner with a reduction of maximum response at the highest antagonist concentration, with the slope values significantly different from unity. Propranolol and ICI 118,551 had no effect on the relaxations elicited by fenoterol, TA 2005, metaproterenol, and ritodrine. Atenolol and 1-[2-((3-carbamoyl-4-hydroxy)phenoxy) ethylamino]-3-[4-(1-methyl-4-trifluoromethyl-2-imidazolyl)-phenoxy]2-propanol methanesulfonate (CGP 20712A) (0.1-10 muM) failed to affect the relaxations induced by all tested beta-adrenoceptor agonists. Our study revealed the existence of two atypical beta-adrenoceptors in the rabbit erectile tissue. Isoproterenol relaxes the rabbit cavernosal tissue by activating atypical beta-adrenoceptors coupled to adenylyl cyclase pathway, whereas the selective beta2-adrenoceptor agonists relax the RbCC tissue through another atypical beta-adrenoceptor subtype coupled to nitric oxide release from the sinusoidal endothelium.

Expression of fibroblast growth factor receptors during development and regression of the bovine corpus luteum

There is evidence that fibroblast growth factors (FGFs) are involved in the regulation of growth and regression of the corpus luteum (CL). However, the expression pattern of most FGF receptors (FGFRs) during CL lifespan is still unknown. The objective of the present study was to determine the pattern of expression of 'B' and 'C' splice variants of FGFRs in the bovine CL. Bovine CL were collected from an abattoir and classed as corpora hemorrhagica (Stage I), developing (Stage II), developed (Stage III) or regressed (Stage IV) CL. Expression of FGFR mRNA was measured by semiquantitative reverse transcription-polymerase chain reaction and FGFR protein was localised by immunohistochemistry. Expression of mRNA encoding the 'B' and 'C' spliced forms of FGFR1 and FGFR2 was readily detectable in the bovine CL and was accompanied by protein localisation. FGFR1C and FGFR2C mRNA expression did not vary throughout CL lifespan, whereas FGFR1B was upregulated in the developed (Stage III) CL. FGFR3B, FGFR3C and FGFR4 expression was inconsistent in the bovine CL. The present data indicate that FGFR1 and FGFR2 splice variants are the main receptors for FGF action in the bovine CL.

Exercise training ameliorates the impairment of endothelial and nitrergic corpus cavernosum responses in diabetic rats

Aims: The effect of exercise training (ET) on vascular responsiveness in diabetes mellitus has been largely well studied. However, limited studies have investigated the effects of ET on functional responses of the corpus cavernosum (CC) in diabetic animals. Therefore, the aim of this study was to investigate whether prior ET prevents the impairment of erectile function in streptozotocin-induced diabetic rats. Main methods: Rats were exercised for four weeks prior to the induction of diabetes, and then again for another 4 weeks thereafter. Concentration-response curves to acetylcholine, sodium nitroprusside, Y-27632, BAY 412272 and phenylephrine (PE) were obtained in CC. The excitatory and inhibitory effects of electrical-field stimulation were also evaluated. Key findings: Plasma SOD levels were markedly decreased in the sedentary diabetic group (D-SD) as compared to control sedentary animals (C-SD), approximately 53% (P < 0.05) and this reduction was restored in trained diabetic animals. Physical training restored the impairment of endothelium-dependent and -independent relaxation responses seen in the D-SD group. The potency values for Y-27632 in the CC were significantly reduced in the D-SD group, which was reversed by physical training. The impairment of electrical-field stimulation (EFS)-induced relaxation seen in the D-SD group was restored by physical training. On the other hand, both EFS-induced contractions and concentration-response curves to PE in cavernosal strips were not modified by either diabetes or physical training. Significance: Practice of regular physical exercise may be an important approach in preventing erectile dysfunction associated with diabetes mellitus by re-establishment of the balance between NO production and its inactivation. © 2010 Elsevier Inc. All rights reserved.

English collocations extracted from a corpus of university learners and its contribution to a language teaching pedagogy

Taking into consideration the relevance of foreign language teaching and the learning of collocations (ALTENBERG; EEG-OLOFSSON, 1990; FONTENELLE, 1994; MEUNIER; GRANGER, 2008), this paper aims at showing results of an investigation on whether the teaching of collocations should be implicit or explicit to the Brazilian university students. Furthermore, the research has the purpose of presenting some collocational aspects from a corpus of the written language learners made up of intermediate, upper intermediate and advanced university students' argumentative essays at a public university in Brazil. With the help of WordSmith Tools (SCOTT, 2007), it was possible to raise students' most frequent collocational choices and patterns, the most/least used type of collocations, the influence of the mother tongue on their choices, among other aspects. With the purpose of motivating and involving students in classroom research, it was also introduced The Corpus of Contemporary American English (COCA), created by Mark Davies. By doing so, students could compare their collocational choices with the patterns found in the online corpus, extract more collocational patterns and, consequently, be aware of the potential of corpora for the foreign learning process, specifically for raising language awareness, with focus on prefabricated chunks.

Localization patterns of steroid and luteinizing hormone receptors in the corpus luteum of Nelore (Bos taurus indicus) cows throughout the estrous cycle

The aim of the present study was to detect progesterone receptors (A and B isoforms), α and β estrogen receptors, luteinizing hormone receptors and aromatase cytochrome P450 enzymes in the corpus luteum of Nelore (Bos taurus indicus) cows using immunohistochemistry. The estrous cycles of 16 Nelore cows were synchronized, and luteal samples were collected via an incision into the vaginal vault. Samples were collected during specific days of the estrous cycle (days 6, 10, 15 and 18) and 24. h after circulating progesterone dropped, after luteolysis had occurred. After each biopsy was taken, all animals were resynchronized so that each biopsy was performed during a different estrous cycle. Our results showed that the concentration of studied proteins vary throughout the bovine estrous cycle. The highest concentration of α and β estrogen receptors and the highest concentration of plasma progesterone were both observed on days 10 and 15 of the estrous cycle. The highest concentration of progesterone receptors was observed on days 6 and 10 of the estrous cycle, and the most intense immunostaining for cytochrome P450 aromatase enzymes was observed on day 10 of the estrous cycle. The highest score of cells with plasma membrane immunostaining for LH receptors was observed on day 15 of the estrous cycle. In conclusion, this study demonstrates the varying concentrations of specific proteins within the corpus luteum of Nelore cows during the estrous cycle. This finding suggests that these receptors and enzymes, and their interactions, are important in regulating luteal viability. © 2013 Elsevier B.V.

Corpus Luteum Development and Function after Supplementation of Long-Acting Progesterone During the Early Luteal Phase in Beef Cattle

Contents: Strategic supplementation of P4 may be used to increase conception rates in cattle, but timing of supplementation in relation to ovulation, mass of supplementary P4 and formulation of the P4-containing supplement has not been determined for beef cattle. Effects of supplementation of long-acting progesterone (P4) on Days 2 or 3 post-ovulation on development, function and regression of corpus luteum (CL) were studied in beef cattle. Cows were synchronized with an oestradiol/P4-based protocol and treated with 150 or 300 mg of long-acting P4 on Day 2 or 3 post-ovulation (6-7 cows/group). Colour-doppler ultrasound scanning and blood sample collection were performed from Day 2-21.5. Plasma P4 concentrations were greater (p < 0.05) from Day 2.5-5.5 in the Day 2-treated groups and from Day 3.5-5.5 in the Day 3-treated cows than in the control group. CL area and blood flow during Day 2-8.5 did not differ (p > 0.05) among groups, suggesting no effect of P4 treatment on luteal development. The frequency of cows that began luteolysis before Day 15 was greater (p < 0.04) in cows treated with 300 mg than in the controls, but there were no differences between non-treated and 150 mg-treated cows. The interval from pre-treatment ovulation to functional and structural luteolysis was shorter (p < 0.01) in the combined P4-treated groups than in the control cows. In conclusion, was showed for the first time that long-acting P4 supplementation on Day 2 or 3 post-ovulation increases P4 concentrations for ≥3 day, has no effect on luteal development, but anticipates the beginning of luteolysis in beef cattle. © 2013 Blackwell Verlag GmbH.

Uma análise da tradução de marcadores culturais em Sergeant Getulio e The Lizard's smile, à luz da linguística de corpus

Pós-graduação em Estudos Linguísticos - IBILCE

Tipologia e uso da voz média em Apolodoro: estudo semântico baseado em corpus

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Ativação microglial, lesão da substância branca e expressão de Nogo-A em ratos submetidos à isquemia estriatal

O objetivo desta investigação foi avaliar o padrão degenerativo de diversos tratos de substância branca após lesão isquêmica estriatal, correlacionando o processo degenerativo com os padrões de ativação microglial e expressão de Nogo-A. Para isso, foi induzida isquemia focal com injeção estereotáxica de endotelina no estriado de ratos adultos, e nos animais controle apenas injetou-se solução salina estéril. Os animais foram perfundidos 3, 7, 14 e 30 dias após isquemia. O cérebro removido, pós-fixado, crioprotegido, cortado em criostato e os cortes obtidos submetidos à investigação imunoistoquímica com os seguintes anticorpos: Anti-GFAP (1:2000,Dako), Anti-Tau-1 (1:500,Chemicon), Anti-MBP (1:100,Chemicon International), Anti-Nogo A (1:100,Invitrogen), Anti-Iba1 (1:1000, WAKO), Anti-ED1 (1:500, Serotec) e Anti-MHC-II (1:100 Abcam), além da visualização do padrão lesivo com violeta de cresila. As lâminas marcadas pelos diferentes métodos foram avaliadas qualitativamente e algumas também quantitativamente (Anti-Nogo A, Anti-ED1, Anti-MHC-II e Anti-Tau-1), com contagens realizadas no estriado e no corpo caloso. Os dados foram tabulados, submetidos à análise estatística pelo teste de Tukey (p<0,05) e capturadas micrografias dos achados mais representativos. As lâminas coradas com violeta de cresila revelaram um aumento da densidade celular pela infiltração de células inflamatórias à área isquêmica, com aumento expressivo ao 7º dia. Nas lâminas imunomarcadas para GFAP foi encontrado aumento progressivo da população de astrócitos, assim como um aumento do volume celular em 7 e 14 dias. Oligondendrócitos patológicos marcados com Tau-1 tiveram pico de marcação ao 3º dia no estriado e ao 7º dia no corpo caloso, e a perda de compactação de mielina identificada pelo MBP foi melhor observada ao 14º dia, nos diferentes tratos. A ativação microglial identificada pelas diferentes imunomarcações apresentou seu pico ao 7º dia, tanto em estriado como em corpo caloso, porém no corpo caloso com um número muito menor quando comparado com o estriado. A morfologia microglial sofreu variações, sendo encontrado o fenótipo ramificado nos animais controles, assim como nos tempos precoces e tardios pós isquemia e o padrão amebóide/fagocítico ao 7º dia, coincidente com o maior número de células ativadas. A contagem de células Nogo-A + teve seu pico observado ao 3º dia no estriado, não sendo observadas no corpo caloso diferenças de expressão de Nogo-A entre 3 a 14 dias, apenas uma diminuição quando comparado a 30 dias. Sendo assim, microinjeções de ET-1 no estriado induziram conspícua perda tecidual, concomitante com ativação microglial progressiva, astrocitose, perda da imunoreatividade para proteína básica de mielina e lesão de oligodendrócitos em diversos tempos de sobrevida após isquemia focal. Estes eventos acometem alguns tratos de SB, como o corpo caloso. O estabelecimento da evolução temporal destes eventos neuropatológico é a base para estudos futuros, nos quais se deverá manipular a resposta inflamatória com intuito de minimizar estas alterações teciduais.

Uma investigação de traduções de textos da área médica sob a luz dos estudos da tradução baseados em corpus

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

A tradução e os prazeres vivos de descobrir o mundo de Clarice Lispector: uma análise comparativa de três obras de Clarice Lispector, traduzidas para o inglês, à luz dos Estudos da Tradução Baseados em Corpus

Pós-graduação em Estudos Linguísticos - IBILCE