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Bradykinin and electrical stimulation increase prostaglandin production in the rat vas deferens
Get PDFThe epididymal portion of the rat vas deferens produced prostaglandins (PG) E2, F2αand 6-keto F1 α. Electrical stimulation (ES, 0.1 Hz, 1 ms) increased such production by 100%, and similar results were obtained in the presence of 1.0 μM bradykinin (Bk). When both stimuli were applied simultaneously, the increases in PG production were 1100% for PGE2, 800% for PGF2αand 400% for PG6-keto F1 α. Prazosin abolished the effect of ES on PG production. A selective Bk B2-receptor antagonist abolished the increase in PG production induced by Bk, both in non-stimulated and in ES tissues. Bk (1.0 μM) elicited contractile responses in non-stimulated as well as in ES tissues, responses that were not modified in the presence of 10 μM indomethacin. In conclusion, the effects of Bk on prostaglandin production appears to depend on the activation of B2receptors, while the increase in prostaglandin release induced by ES, and the effects observed with both stimuli simultaneously, should be mediated by the release of noradrenaline and the subsequent activation of α1adrenoceptors.Fil: Peredo, Horacio Angel. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. ININFA; ArgentinaFil: Celuch, Stella Maris. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. ININFA; Argentin
Fisiopatologia de la hipertensión arterial en el síndrome metabólico y la insulinoresistencia
Get PDF1. Se denomina síndrome metabólico a un conjunto de factores de riesgo cardiovascular que incluye diabetes, obesidad, dislipidemia e hipertensión arterial, que suelen aparecer con frecuencia en la práctica clínica. 2. La resistencia a la insulina puede ser definida como la incapacidad de esta de producir sus numerosos efectos, aun en presencia de una secreción normal de las células β. 3. Estudios clínicos demuestran que dos tercios de la prevalencia de hipertensión arterial son atribuibles a la obesidad. Además, estudios experimentales muestran que el exceso de peso incrementa la presión arterial. 4. En el modelo experimental de sobrecarga de fructosa en la rata se encontraron alteraciones a nivel hipotalámico del sistema nervioso simpático, así como también modificaciones en la secreción de sustancias vasoactivas endoteliales.Fil: Mayer, Marcos Alejandro. Universidad Nacional de La Pampa; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Confluencia; ArgentinaFil: Peredo, Horacio Angel. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay; ArgentinaFil: Puyó, Ana María. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Biología Celular e Histología; Argentin
A high-fat plus fructose diet produces a vascular prostanoid alterations in the rat
Get PDFIn the rat, a high-fat (HF) plus fructose (F) diet produces cardiovascular and metabolic alterations that resemble human metabolic syndrome. Prostanoids (PR), cyclo-oxygenase-derived arachidonic acid metabolites, have vasoactive properties and mediate inflammation. The aim of this study was to analyse the effect of a HF+F diet on blood pressure (BP), metabolic parameters and mesenteric vascular bed PR production in male Sprague-Dawley rats. Four groups were studied over 9 weeks (n = 6 each): control (C), standard diet (SD) and tap water to drink; F+SD and 10% w/v F solution to drink; HF 50% (w/w) bovine fat added to SD and tap water; and HFF, both treatments. PR were determined by HPLC. Blood pressure was elevated in all experimental groups. Triglyceridaemia, insulinaemia and HOMA-IR were increased in the F and HF groups. HF+F animals showed elevated glycaemia, insulinaemia, HOMA-IR and triglyceridaemia. F decreased the vasodilator prostanoids PGI2 and PGE2 in the mesenteric vascular bed. Body weight was not significantly altered. In HFF, production of PGE2, PGF2alpha and TXB2 was elevated. The increased BP in HF and HFF could be partly attributed to the imbalance in vascular PR production towards vasoconstrictors. On the other hand, this dietary modification could induce inflammation, which would explain the elevation of PGE2. In the F group, hypertension could be related to decreased vasodilator PRs. The simultaneous administration of HF and F in the rat produces deleterious effects greater than observed when treatments are applied separately.Fil: Peredo, Horacio Angel. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Lee, H.. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica; ArgentinaFil: Donoso, Adriana Susana. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica; ArgentinaFil: Andrade, V.. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica; ArgentinaFil: Sánchez Eluchans, N.. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica; ArgentinaFil: Puyó, Ana María. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica; Argentin
Sodium Tungstate and Vanadyl Sulfate Effects on Blood Pressure and Vascular Prostanoids Production in Fructose-Overloaded Rats
Get PDFThis study analyzes the effects of sodium tungstate and vanadyl sulphate in the fructose-overloaded rat, a model of metabolic syndrome. Fructose (9 weeks) increased blood pressure, triglycerydemia, glycemia, and reduced release of vasodilator prostaglandins (prostacyclin and prostaglandin E2) in the mesenteric vascular bed. Sodium tungstate prevented those alterations; meanwhile vanadyl sulfate only prevented the increase in glycemia. In conclusion, the present experiments showed that sodium tungstate is more effective than vanadyl sulfate for the treatment of experimental metabolic syndrome in rats.Fil: Peredo, Horacio Angel. Universidad de Buenos Aires. Facultad de Medicina; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay; ArgentinaFil: Zabalza, Maria. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Ciencias Biológicas. Cátedra de Histología y Biología Celular; ArgentinaFil: Mayer, Marcos Alejandro. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Fisiopatología y Bioquímica Clínica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay; ArgentinaFil: Carranza, Andrea. Universidad de Buenos Aires. Facultad de Medicina; ArgentinaFil: Puyó, Ana María. Universidad de Buenos Aires. Facultad de Medicina; Argentin
Sodium molybdate prevents hypertension and vascular prostanoid imbalance in fructose overloaded rats
Get PDF1. Fructose (F) overload produces elevated blood pressure (BP), hyperglycaemia, hypertriglyceridemia and insulin resistance, resembling human metabolic syndrome. Previously, we found altered vascular prostanoid (PR) production in this model. 2. Sodium molybdate (Mo), as well as sodium tungstate, causes insulin-like effects and normalizes plasma glucose levels in streptozotocin-treated diabetic rats. We studied the effects of Mo on BP, metabolic parameters and release of PR from the mesenteric vascular bed (MVB) in F-overloaded rats.
3. Four groups of male Sprague-Dawley rats were analysed: Control, tap water to drink; F, F solution 10% W/V to drink; CMo, Mo 100 mg kg day 1 and FMo, both treatments. After 9 weeks, the animals were killed and MVBs removed and the released PRs measured.
4. F increased BP, glycemia, triglyceridemia and insulinemia. Mo treatment prevented the increases in BP and glycemia, but did not modify triglyceridemia or insulinemia. In addition, Mo decreased BP in controls.
5. Prostaglandins (PG) F2alpha and E2, PG 6-ketoF1alpha and thromboxane (TX) B2, as well as inactive metabolites of prostacyclin (PGI2) and TXA2 were detected. F decreased the production of vasodilator PRs PGI2 and PGE2 in MVB. Mo prevented these alterations and increased PGE2 in controls. Vasoconstrict or PRs PGF2alpha and TXA2 release was not modified.
6. Mo treatment, beyond its known lowering effect on glycemia, prevents the reduction in the vascular release of vasodilator PR observed in this model. This could be one of the mechanisms by which Mo avoids the increase in BP caused by F overload in the rat.Fil: Peredo, Horacio Angel. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Tecnología Farmacéutica; Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay; Argentina;Fil: Andrade, V.. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica; Argentina;Fil: Donoso, Adriana Susana. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Ciencias Biológicas; Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay; Argentina;Fil: Lee, H. J.. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica; Argentina;Fil: Puyó, Ana María. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Ciencias Biológicas; Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay; Argentina
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Prostanoides y lecho vascular mesentérico: su implicancia en enfermedades cardiometabólicas
Get PDFLas enfermedades metabólicas como el síndrome metabólico y la diabetes mellitus tipo 2 están estrechamente vinculadas con la hipertensión arterial y constituyen un importante problema de salud pública a nivel mundial. Sin embargo, la relación exacta entre las mismas aún no está completamente dilucidada. El lecho vascular mesentérico constituye una fuente de prostanoides formada por las prostaglandinas (PGs) y tromboxanos (TXs). Estos mediadores lipídicos juegan un importante papel en la regulación del tono vasomotor. Recientemente se ha aumentado el interés en el estudio de la función del lecho mesentérico en estas enfermedades. Alteraciones en la función del tejido adiposo perivascular localizado alrededor de los vasos mesentéricos inducida por alteraciones de la dieta podrían constituir un posible vínculo entre las alteraciones metabólicas y el desarrollo de enfermedades cardiovasculares como la hipertensión arterial. Un estudio realizado por nuestro laboratorio mostró un patrón alterado de la liberación de prostanoides en el lecho vascular mesentérico en un modelo experimental de síndrome metabólico en la rata inducida por una dieta alta en grasa.Metabolic diseases such as metabolic syndrome and type 2 diabetes mellitus are closely linked to hypertension and constitute a major public health problem worldwide. However, the exact relationship between them is not yet fully understood. The mesenteric vascular bed constitutes a source of prostanoids such as prostaglandins (PGs) and thromboxanes (TXs). These lipid mediators play an important role in the regulation of vasomotor tone. Recently, the interest in the study of mesenteric bed function in these diseases has been aroused. Alterations in the function of perivascular adipose tissue located in the mesenteric vessels induced by dietary alterations could constitute a possible link between metabolic alterations and the development of cardiovascular diseases such as hypertension. To address these issues, we present the results of a study of our laboratory showing an altered pattern of prostanoid release in the mesenteric vascular bed in an experimental model of metabolic syndrome in rats induced by a high fat diet.Fil: Lee, Hyun Jin. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Ciencias Biológicas. Cátedra de Histología y Biología Celular; ArgentinaFil: Cantú, Silvana María. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Ciencias Biológicas. Cátedra de Histología y Biología Celular; ArgentinaFil: Donoso, Adriana Susana. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Ciencias Biológicas. Cátedra de Histología y Biología Celular; ArgentinaFil: Choi, Marcelo Roberto. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Ciencias Biológicas. Cátedra de Histología y Biología Celular; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Peredo, Horacio Angel. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Ciencias Biológicas. Cátedra de Histología y Biología Celular; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Puyó, Ana María. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Ciencias Biológicas. Cátedra de Histología y Biología Celular; Argentin
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
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