NF-kB overexpression and decreased immunoexpression of AR in the muscular layer is related to structural damages and apoptosis in cimetidine-treated rat vas deferens

Background: Cimetidine, histamine H2 receptors antagonist, has caused adverse effects on the male hormones and reproductive tract due to its antiandrogenic effect. In the testes, peritubular myoid cells and muscle vascular cells death has been associated to seminiferous tubules and testicular microvascularization damages, respectively. Either androgen or histamine H2 receptors have been detected in the mucosa and smooth muscular layer of vas deferens. Thus, the effect of cimetidine on this androgen and histamine-dependent muscular duct was morphologically evaluated.Methods: The animals from cimetidine group (CMTG; n=5) received intraperitoneal injections of 100 mg/kg b.w. of cimetidine for 50 days; the control group (CG) received saline solution. The distal portions of vas deferens were fixed in formaldehyde and embedded in paraffin. Massońs trichrome-stained sections were subjected to morphological and the following morphometrical analyzes: epithelial perimeter and area of the smooth muscular layer. TUNEL (Terminal deoxynucleotidyl-transferase mediated dUTP Nick End Labeling) method, NF-kB (nuclear factor kappa B) and AR (androgen receptors) immunohistochemical detection were also carried out. The birefringent collagen of the muscular layer was quantified in picrosirius red-stained sections under polarized light. The muscular layer was also evaluated under Transmission Electron Microscopy (TEM).Results: In CMTG, the mucosa of vas deferens was intensely folded; the epithelial cells showed numerous pyknotic nuclei and the epithelial perimeter and the area of the muscular layer decreased significantly. Numerous TUNEL-labeled nuclei were found either in the epithelial cells, mainly basal cells, or in the smooth muscle cells which also showed typical features of apoptosis under TEM. While an enhanced NF-kB immunoexpression was found in the cytoplasm of muscle cells, a weak AR immunolabeling was detected in these cells. In CMTG, no significant difference was observed in the birefringent collagen content of the muscular layer in comparison to CG.Conclusions: Cimetidine induces significant damages in the epithelium; a possible antiandrogenic effect on the basal cells turnover should be considered. The cimetidine-induced muscle cells apoptosis confirms the susceptibility of these cells to this drug. The parallelism between enhanced cytoplasmic NF-kB immunolabeling in the damaged muscular tissue and muscle cell apoptosis suggests that this drug may avoid the translocation of NF-kB to the nucleus and interfere in the control of NF-kB-mediated smooth muscle cell apoptosis. The decreased immunoexpression of ARs verified in the damaged muscular tissue reinforces this possibility. © 2013 Koshimizu et al.; licensee BioMed Central Ltd.

Medio ambiente en la planificación latinoamericana: vías para una mayor incorporación

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Ejecución del Plan de Acción de Río de Janeiro para la Cooperación entre Países en Vías de Desarrollo en el Campo de las Fuentes de Energía Nuevas y Renovables" = Implementation of the "Rio de Janeiro Plan of Action for the Co-operation among Developing Countries in the Field of New and Renewable Sources of Energy""

Señala algunas actividades concretas que podrían iniciar los países en desarrollo para la cooperación en el campo de las fuentes de energía nuevas y renovables. Dichas actividades consisten en una serie de programas que, según su naturaleza, se clasifican en: a) programa de planificación energética, b) programa de desarrollo científico y tecnológico, y c) programas de apoyo comunes.

Diseño de cuestionarios de encuestas del hogar para los países en vías de desarrollo: lecciones de diez años de experiencia con las EMNV: capítulo 17: Consumo

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Medio ambiente en la planificación latinoamericana: vías para una mayor incorporación

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C-TPAT Y AEO: Las nuevas vías del comercio internacional

La presente edición del Boletín FAL analiza los requisitos y ventajas ofrecidos por el programa Alianza Aduanas-Empresarial Contra el Terrorismo (C-TPAT por sus siglas en inglés) de los Estados Unidos y el Operador Económico Autorizado (AEO por sus siglas en inglés) implementado por la Unión Europea.La seguridad en la cadena de suministros, especialmente en alimentos, ha ganado significativa relevancia en los últimos años, debido a una conjugación de diversos factores emergentes - o de creciente importancia - que han hecho de la capacidad para asegurar la inocuidad de una carga, un requisito cada vez más indispensable y valioso al momento de las negociaciones comerciales. En el orden de certificar el estado inofensivo de un cargamento, varias normas del sector privado han surgido en todo el mundo, no obstante, los beneficios que presentan el programa C-TPAT y el AEO, se encuentran aún muy por encima de sus equivalentes privados.Como primer paso en esta dirección, analizar los programas de los dos mayores mercados de la región (Estados Unidos y la Unión Europea) de manera comparada, es importante para que el exportador latinoamericano y caribeño disponga de la información necesaria a fin de modificar y/o adecuar sus instalaciones y procedimientos de producción, con el objetivo de lograr un mejor ingreso a los mercados.

Morphometric evaluation of the rat testis, epididymis and vas deferens following chemical sympathectomy with guanethidine

Selective chemical sympathectomy of the internal sex organs of adult male rats was undertaken by long term administration of low doses of guanethidine. The spermatogenic activity of the testis was unaffected by treatment. Examination of the vas deferens using morphometric methods revealed a marked increase in luminal area in contrast to a decrease in muscle layer area and in epithelial height. This is morphological evidence of sperm accumulation caused by a disorder in ductal contractile activity. No structural changes were observed in the epididymis. However, the concentration of spermatozoa in the sperm suspension stored in the cauda epididymidis was significantly increased in denervated rats. This result is discussed in terms of a sympathetic control of resorption mechanisms in the epididymis.