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1.
Clín. investig. arterioscler. (Ed. impr.) ; 30(5): 209-216, sept.-oct. 2018. ilus, tab, graf
Article in Spanish | IBECS | ID: ibc-175438

ABSTRACT

Introducción: El resveratrol tiene propiedades antiinflamatorias y antiaterogénicas; sin embargo, se desconoce su efecto sobre el factor de crecimiento endotelial vascular (VEGF) en la aterosclerosis. Objetivo: Evaluar el efecto del resveratrol sobre las concentraciones séricas del VEGF durante la progresión y evolución de la aterosclerosis y su evolución en el tiempo en conejos alimentados con dieta enriquecida con colesterol. Materiales y métodos: Cuarenta y ocho conejos machos divididos en cuatro grupos de 12 conejos recibieron: grupo 1 (control): conejarina; grupo 2: conejarina suplementada con 0,5% colesterol; grupo 3 (control resveratrol): conejarina y resveratrol (2 mg/kg); grupo 4: conejarina suplementada con 0,5% colesterol y resveratrol, durante 12 semanas. Se realizaron determinaciones séricas de triglicéridos, colesterol y sus fracciones, VEGF y proteína C reactiva (PCR) al inicio, a la 6.a y a la 12.a semana de experimentación. La mitad de los conejos fueron sacrificados a la 6.a y a la 12.a semana y se realizó estudio histológico de su aorta. Resultados: El VEGF y la PCR aumentaron en los grupos2 y 4 desde la 6.a semana de experimentación con respecto a los grupos 1 y 3, respectivamente (p < 0,001). En la duodécima semana se observó una disminución de los niveles de VEGF y PCR en el grupo 4 con respecto al grupo 2 (p < 0,004). El tratamiento con resveratrol disminuyó la formación de ateromas. Conclusiones: El VEGF y la PCR séricos constituyen marcadores tempranos no invasivos de inflamación y aterosclerosis. La suplementación oral de resveratrol ejerce efectos antiinflamatorios y antiateroscleróticos, disminuyendo las concentraciones séricas de VEGF y PCR, y la formación y evolución de las lesiones ateroscleróticas


Introduction: Although it is known that resveratrol has anti-inflammatory and anti-atherogenic actions, its effect on vascular endothelial growth factor (VEGF) in atherosclerosis is unknown. Objective: To evaluate the effect of resveratrol on serum concentrations of VEGF during the progression and evolution of atherosclerosis, as well as and its evolution over time in rabbits fed with a cholesterol diet. Materials and methods: A total of 48 New Zealand white male rabbits were randomly divided into four groups of 12 rabbits: group 1 (control): standard diet (commercial rabbit food); group 2: cholesterol diet (0.5% cholesterol); group 3 (control resveratrol): standard diet (commercial rabbit food) and resveratrol (2 mg/Kg); group 4: cholesterol diet (0.5% cholesterol) and resveratrol (2 mg/Kg), for 12 weeks. Blood samples of overnight-fasted rabbits were collected at baseline and the sixth and twelfth weeks, and the lipid profile, VEGF, and C-reactive protein (CRP) levels were determined. Half of the animals were sacrificed on the sixth or twelfth week, and the aorta was dissected for histological studies. Results: VEGF and CRP levels were significantly higher in groups 2 and 4 than in groups1 and 3, respectively, from the 6th week (p < 0.001). VEGF and CRP were significantly lower in group 4 than in group 2 on 12 th week (p < 0.004). Supplementation of resveratrol reduced the formation of atherosclerotic lesions. Conclusions: Serum VEGF and CRP levels are early markers of atherosclerosis. Oral supplementation of resveratrol exerts anti-inflammatory and anti-atherosclerotic effects, decreasing serum concentrations of VEGF and CRP and the formation and evolution of atherosclerotic lesions


Subject(s)
Animals , Rabbits , Atherosclerosis/physiopathology , Vascular Endothelial Growth Factors/blood , Anti-Inflammatory Agents, Non-Steroidal/therapeutic use , Atherosclerosis/drug therapy , Vascular Endothelial Growth Factors , Cholesterol, Dietary , Rabbits/metabolism , Triglycerides/analysis , C-Reactive Protein/analysis , Biomarkers
2.
Clin Investig Arterioscler ; 30(5): 209-216, 2018.
Article in English, Spanish | MEDLINE | ID: mdl-30253861

ABSTRACT

INTRODUCTION: Although it is known that resveratrol has anti-inflammatory and anti-atherogenic actions, its effect on vascular endothelial growth factor (VEGF) in atherosclerosis is unknown. OBJECTIVE: To evaluate the effect of resveratrol on serum concentrations of VEGF during the progression and evolution of atherosclerosis, as well as and its evolution over time in rabbits fed with a cholesterol diet. MATERIALS AND METHODS: A total of 48 New Zealand white male rabbits were randomly divided into four groups of 12 rabbits: group1 (control): standard diet (commercial rabbit food); group2: cholesterol diet (0.5% cholesterol); group3 (control resveratrol): standard diet (commercial rabbit food) and resveratrol (2mg/Kg); group4: cholesterol diet (0.5% cholesterol) and resveratrol (2mg/Kg), for 12weeks. Blood samples of overnight-fasted rabbits were collected at baseline and the sixth and twelfth weeks, and the lipid profile, VEGF, and C-reactive protein (CRP) levels were determined. Half of the animals were sacrificed on the sixth or twelfth week, and the aorta was dissected for histological studies. RESULTS: VEGF and CRP levels were significantly higher in groups2 and 4 than in groups1 and 3, respectively, from the 6th week (p<0.001). VEGF and CRP were significantly lower in group4 than in group2 on 12th week (p<0.004). Supplementation of resveratrol reduced the formation of atherosclerotic lesions. CONCLUSIONS: Serum VEGF and CRP levels are early markers of atherosclerosis. Oral supplementation of resveratrol exerts anti-inflammatory and anti-atherosclerotic effects, decreasing serum concentrations of VEGF and CRP and the formation and evolution of atherosclerotic lesions.


Subject(s)
Anti-Inflammatory Agents, Non-Steroidal/pharmacology , Atherosclerosis/drug therapy , Resveratrol/pharmacology , Vascular Endothelial Growth Factor A/blood , Animals , Aorta/pathology , Atherosclerosis/blood , Atherosclerosis/pathology , C-Reactive Protein/metabolism , Cholesterol, Dietary/administration & dosage , Lipids/blood , Male , Rabbits
3.
J Mol Neurosci ; 62(3-4): 281-290, 2017 Aug.
Article in English | MEDLINE | ID: mdl-28653133

ABSTRACT

Adrenomedullin (AM) is a peptide involved in blood pressure regulation. AM activates three different receptors, the AM type 1 (AM1), type 2 (AM2), and calcitonin gene-related peptide 1 (CGRP1) receptors. AM triggers several signaling pathways such as adenylyl cyclase (AC), guanylyl cyclase (GC), and extracellular signal-regulated kinases (ERK) and modulates reactive oxygen species (ROS) metabolism. Cerebellar AM, AM-binding sites, and its receptor components are altered during hypertension, although it is unknown if these alterations are associated with changes in AM signaling. Thus, we assessed AM signaling pathways in cerebellar vermis of 16-week-old Wistar Kyoto (WKY) and spontaneously hypertensive rats (SHR). Animals were sacrificed by decapitation, and cerebellar vermis was microdissected under stereomicroscopic control. Tissue was stimulated in vitro with AM. Then the production of cyclic guanosine monophosphate (cGMP), nitric oxide (NO) and cyclic adenosine monophosphate (cAMP) were assessed along with ERK1/2 activation and three antioxidant enzymes' activity: glutathione peroxidase (GPx), catalase (CAT), and superoxide dismutase (SOD). Our findings demonstrate that in the cerebellar vermis of normotensive rats, AM increases cGMP, NO, cAMP production, and ERK1/2 phosphorylation, while decreases basal antioxidant enzyme activity. In addition, AM antagonizes angiotensin II (ANG II)-induced increment of antioxidant enzyme activity. Hypertension blunts AM-induced cGMP and NO production and AM-induced decrease of antioxidant enzyme activity. Meanwhile, AM-induced effects on cAMP production, ERK1/2 activation, and AM-ANG II antagonism were not altered in SHR rats. Our results support a dysregulation of several AM signaling pathways during hypertension in cerebellar vermis.


Subject(s)
Adrenomedullin/metabolism , Cerebellum/metabolism , Hypertension/metabolism , MAP Kinase Signaling System , Animals , Catalase/metabolism , Cyclic GMP/metabolism , Glutathione Peroxidase/metabolism , Male , Mitogen-Activated Protein Kinase 1/metabolism , Mitogen-Activated Protein Kinase 3/metabolism , Rats , Rats, Inbred SHR , Rats, Inbred WKY , Superoxide Dismutase/metabolism
5.
Cerebellum ; 16(1): 132-141, 2017 02.
Article in English | MEDLINE | ID: mdl-27108271

ABSTRACT

Adrenomedullin (AM) and its receptors components, calcitonin-receptor-like receptor (CRLR), and receptor activity-modifying protein (RAMP1, RAMP2, and RAMP3) are expressed in cerebellum. Cerebellar AM, AM binding sites and receptor components are altered during hypertension, suggesting a role for cerebellar AM in blood pressure regulation. Thus, we assessed the effect of valsartan, on AM and its receptor components expression in the cerebellar vermis of Wistar Kyoto (WKY) and spontaneously hypertensive (SHR) rats. Additionally, we evaluated AM action on superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx) activity, and thiobarbituric acid reactive substances (TBARS) production in cerebellar vermis. Animals were treated with valsartan or vehicle for 11 days. Rats were sacrificed by decapitation; cerebellar vermis was dissected; and AM, CRLR, RAMP1, RAMP2, and RAMP3 expression was quantified by Western blot analysis. CAT, SOD, and GPx activity was determined spectrophotometrically and blood pressure by non-invasive plethysmography. We demonstrate that AM and RAMP2 expression was lower in cerebellum of SHR rats, while CRLR, RAMP1, and RAMP3 expression was higher than those of WKY rats. AM reduced cerebellar CAT, SOD, GPx activities, and TBARS production in WKY rats, but not in SHR rats. Valsartan reduced blood pressure and reversed the altered expression of AM and its receptors components, as well the loss of AM capacity to reduce antioxidant enzyme activity and TBARS production in SHR rats. These findings demonstrate that valsartan is able to reverse the dysregulation of cerebellar adrenomedullinergic system; and they suggest that altered AM system in the cerebellum could represent the primary abnormality leading to hypertension.


Subject(s)
Adrenomedullin/metabolism , Antihypertensive Agents/pharmacology , Cerebellum/drug effects , Hypertension/drug therapy , Valsartan/pharmacology , Angiotensin II Type 1 Receptor Blockers/pharmacology , Animals , Catalase/metabolism , Cerebellum/metabolism , Disease Models, Animal , Glutathione Peroxidase/metabolism , Hypertension/metabolism , Male , Random Allocation , Rats, Inbred SHR , Rats, Inbred WKY , Receptor Activity-Modifying Protein 1/metabolism , Receptor Activity-Modifying Protein 2/metabolism , Receptor Activity-Modifying Protein 3/metabolism , Superoxide Dismutase/metabolism , Thiobarbituric Acid Reactive Substances/metabolism
6.
Adv Exp Med Biol ; 956: 541-560, 2017.
Article in English | MEDLINE | ID: mdl-27614623

ABSTRACT

Adrenomedullin (AM) is a multifunctional peptide which exerts numerous biological activities through the activation of AM1 (CRLR + RAMP2) and AM2 (CRLR + RAMP3) receptors. AM immunoreactivity, AM binding sites and CRLR, RAMP1, RAMP2 and RAMP3 are expressed in rat cerebellar vermis. AM binding sites are discretely and differentially distributed in the rat cerebellar cortex with higher levels detected in SHR when compared with WKY rats. In addition, there is an up-regulation of cerebellar CGRP1 (CRLR + RAMP1) and AM2 (CRLR + RAMP3) receptors and a down-regulation of AM1 (CRLR + RAMP2) receptor during hypertension associated with a decreased AM expression. These changes may constitute a mechanism which contributes to the development of hypertension, and supports the notion that cerebellar AM is involved in the regulation of blood pressure. Cerebellar AM activates ERK, increases cAMP, cGMP and nitric oxide, and decreases antioxidant enzyme activity. These effects are mediated through AM1 receptor since they are blunted by AM(22-52). AM-stimulated cAMP production is mediated through AM2 and CGRP receptors. In vivo administration of AM into the cerebellar vermis caused a profound, specific and dose-dependent hypotensive effect in SHR, but not in normotensive WKY rats. This effect was mediated through AM1 receptor since it was abolished by AM(22-52). In addition, AM injected into the cerebellar vermis reduced vasopressor response to footshock stress. These findings demonstrate dysregulation of cerebellar AM system during hypertension, and suggest that cerebellar AM plays an important role in the regulation of blood pressure. Likewise, they constitute a novel mechanism of blood pressure control which has not been described so far.


Subject(s)
Adrenomedullin/metabolism , Blood Pressure , Cardiovascular System/metabolism , Cerebellum/metabolism , Hypertension/metabolism , Animals , Antihypertensive Agents/therapeutic use , Blood Pressure/drug effects , Cardiovascular System/drug effects , Cardiovascular System/physiopathology , Cerebellum/drug effects , Cerebellum/physiopathology , Humans , Hypertension/drug therapy , Hypertension/physiopathology , Receptors, Adrenomedullin/metabolism , Signal Transduction
7.
Invest. clín ; 57(3): 280-292, Sept. 2016. ilus, graf
Article in Spanish | LILACS | ID: biblio-841118

ABSTRACT

La adrenomedulina (AM) es un péptido involucrado en la regulación cardiovascular. En el cerebelo, la densidad de los receptores de la AM se encuentra alterada durante la hipertensión, sugiriendo un posible papel del sistema adrenomedulinérgico cerebelar en la regulación de la presión arterial (PA). El objetivo del presente estudio fue evaluar el efecto funcional in vivo de la AM durante el estrés agudo, mediante la administración in situ de AM en el vermis cerebelar de la rata. Se emplearon ratas adultas normotensas Wistar Kyoto (WKY) y Sprague Dawley (SD) y ratas espontáneamente hipertensas (SHR) las cuales fueron anestesiadas y posteriormente canuladas en el vermis cerebelar. El estrés se indujo mediante el uso del estímulo eléctrico plantar (EEP). Los animales fueron divididos en grupos que recibieron AM (0,2 o 200 pmol/5μL) o vehículo (solución fisiológica, 5μL). La PA se determinó antes del experimento y después de la administración del tratamiento respectivo, seguida de la aplicación del EEP (100 V, 5 Hz, 10 mseg, durante 4 minutos). La PA se determinó mediante pletismografía digital no invasiva. Los resultados demuestran que la microinyección de AM (0,2 y 200 pmol) in situ en el vermis cerebeloso en ratas SD, WKY y SHR disminuye significativamente la respuesta presora frente al estrés inducido por el EEP, lo que sugiere que la acción hipotensora está mediada a través de la regulación del eflujo simpático. Estos hallazgos demuestran la participación de la AM cerebelosa en la regulación de la respuesta cardiovascu lar frente al estrés.


Adrenomedullin (AM) is a peptide involved in cardiovascular regulation. In the cerebellum, the density of AM receptors is altered during hypertension, suggesting a pos sible role of cerebellar adrenomedulinergic system in the regulation of blood pressure (BP). The aim of this study was to evaluate the functional role of AM during acute stress, by in situ administration of AM into the cerebellar vermis in rats. Adult normotensive Wistar Kyoto (WKY) and Sprague Dawley (SD) rats and spontaneously hypertensive rats (SHR), were anes thetized and their cerebellar vermis cannulated. Footshock was used as stressor. Animals were divided into groups that received either AM (0.2 and 200 pmol/5μL) or vehicle (physiological saline, 5μL). The BP was determined, using noninvasive digital plethysmography, before and after treatment, followed by footshock (100V, 5 Hz, 10 msec, for 4 minutes). The results show that microinjection of AM (0.2 and 200 pmol) in situ into the cerebellar vermis in SD, WKY and SHR rats, significantly decreased the pressor response induced by footshock stress, sugges ting that the hypotensive action is mediated through regulation of sympathetic outflow. Taken together, our results demonstrate a role of cerebellar AM in the regulation of cardiovascular response to stress.


Subject(s)
Animals , Male , Stress, Physiological/physiology , Cerebellum/physiology , Adrenomedullin/physiology , Rats, Wistar , Rats, Sprague-Dawley
8.
Invest Clin ; 57(3): 280-92, 2016 Sep.
Article in Spanish | MEDLINE | ID: mdl-29938483

ABSTRACT

Adrenomedullin (AM) is a peptide involved in cardiovascular regulation. In the cerebellum, the density of AM receptors is altered during hypertension, suggesting a possible role of cerebellar adrenomedulinergic system in the regulation of blood pressure (BP). The aim of this study was to evaluate the functional role of AM during acute stress, by in situ administration of AM into the cerebellar vermis in rats. Adult normotensive Wistar Kyoto (WKY) and Sprague Dawley (SD) rats and spontaneously hypertensive rats (SHR), were anesthetized and later, their cerebellar vermis cannulated. Footshock was used as stressor. Animals were divided into groups that received either AM (0.2 and 200 pmol/5µL) or vehicle (physiological saline, 5µL). The BP was determined, using noninvasive digital plethysmography, before and after treatment, followed by the application of footshock (100V, 5 Hz, 10 msec, for 4 minutes). The results show that microinjection of AM (0.2 and 200 pmol) in situ into the cerebellar vermis in SD, WKY and SHR rats, significantly decreased the pressor response induced by footshock stress, suggesting that the hypotensive action is mediated through regulation of sympathetic outflow. Taken together, our results demonstrate a role of cerebellar AM in the regulation of cardiovascular response to stress.


Subject(s)
Adrenomedullin/physiology , Cerebellum/physiology , Stress, Physiological/physiology , Animals , Male , Rats, Sprague-Dawley , Rats, Wistar
9.
Neuropeptides ; 54: 59-66, 2015 Dec.
Article in English | MEDLINE | ID: mdl-26259851

ABSTRACT

Adrenomedullin (AM) and their receptor components, calcitonin-receptor-like receptor (CRLR) and receptor activity-modifying protein (RAMP1, RMP2 and RAMP3) are widely expressed in the central nervous system, including cerebellum. We have shown that AM binding sites are altered in cerebellum during hypertension, suggesting a role for cerebellar adrenomedullinergic system in blood pressure regulation. To further evaluate the role of AM in cerebellum, we assessed the expression of AM, RAMP1, RAMP2, RAMP3 and CRLR in the cerebellar vermis of 8 and 16week old spontaneously hypertensive (SHR) and normotensive Wistar Kyoto (WKY) rats. In addition, the effect of microinjection of AM into rat cerebellar vermis on arterial blood pressure (BP) was determined. Animals were sacrificed by decapitation and cerebellar vermis was dissected for quantification of AM, CRLR, RAMP1, RAMP2 and RAMP3 expression using western blot analysis. Another group of male, 16week old SHR and WKY rats was anesthetized, and a cannula was implanted in the cerebellar vermis. Following recovery AM (0.02 to 200pmol/5µL) or vehicle was injected into cerebellar vermis. BP was determined, before and after treatments, by non-invasive plethysmography. In addition, to establish the receptor subtype involved in AM action in vivo, animals received microinjections of AM22-52 (200pmol/5µL), an AM1 receptor antagonist, or the CGRP1 receptor antagonist, CGRP8-37 (200pmol/5µL) into the cerebellar vermis, administered simultaneously with AM or vehicle microinjection. Cannulation was verified post mortem with the in situ injection of a dye solution. Our findings demonstrated that the expression of CRLR, RAMP1 and RAMP3 was higher in cerebellum of SHR rats, while AM and RAMP2 expression was lower than those of WKY rats, both in 8 and 16week old rats. In vivo microinjection of AM into the cerebellar vermis caused a profound, dose dependent, hypotensive effect in SHR but not in normotensive WKY rats. Coinjections of a putative AM receptor antagonist, AM22-52 abolished the decreases in mean arterial pressure (MAP) evoked by AM, showing that AM acts through its AM1 receptor in the vermis to reduce MAP. These findings demonstrate a dysregulation of cerebellar AM-system during hypertension, and suggest that cerebellar AM plays an important role in the regulation of BP. Likewise; they constitute a novel mechanism of BP control which has not been described so far.


Subject(s)
Adrenomedullin/physiology , Blood Pressure , Cerebellar Vermis/physiology , Hypertension/metabolism , Hypertension/physiopathology , Receptor Activity-Modifying Proteins/metabolism , Adrenomedullin/administration & dosage , Adrenomedullin/metabolism , Animals , Arterial Pressure/drug effects , Calcitonin Gene-Related Peptide/administration & dosage , Calcitonin Receptor-Like Protein/metabolism , Cerebellar Vermis/drug effects , Cerebellar Vermis/metabolism , Male , Peptide Fragments/administration & dosage , Rats , Rats, Inbred SHR , Rats, Inbred WKY , Receptor Activity-Modifying Protein 1/metabolism , Receptor Activity-Modifying Protein 2/metabolism , Receptor Activity-Modifying Protein 3/metabolism
10.
Caracas; s.n; oct. 2012. ^c30 cmtab, ilus, graf. (Itf1482012615833).
Thesis in Spanish | LIVECS, LILACS | ID: biblio-1150991

ABSTRACT

La adrenomedulina (AM) es un péptido ubicuo de 52 residuos de aminoácidos que cumple funciones importantes en la regulación de la función cardiovascular (CDV). La AM ejerce sus acciones a través de su unión con tres subtipos de receptores, el receptor del péptido relacionado al gen de la calcitonina tipo 1 (CGRP1), el receptor de AM tipo 1 (AM1) y tipo 2 (AM2). El CGRP1 está formado por el receptor similar al receptor de calcitonina (CRLR) y la proteína que modifica la actividad del receptor tipo 1 (RAMP1). El AM1 por el CRLR+RAMP2 y el AM2 por el CRLR+RAMP3. A nivel del sistema nervioso central, la AM y sus receptores se localizan en diversas regiones, incluyendo el cerebelo. Se ha demostrado marcados incrementos en la densidad de los sitios de unión para la AM en el cerebelo durante la hipertensión, lo que sugiere un papel del sistema adrenomedulinérgico cerebeloso en la regulación de la presión arterial (PA). En el presente estudio se evaluó la participación de la AM cerebelosa en la regulación de la PA. Nuestros hallazgos muestran la existencia de desregulación de los componentes del sistema AM cerebeloso durante la hipertensión, ya que se encontró una reducida expresión de CRLR, RAMP1 y RAMP3 y una incrementada expresión de la AM y RAMP2 en el vermis de cerebelo de ratas hipertensas (SHR), cuando se comparó con las ratas controles, Wistar Kyoto (WKY), de 8 y 16 semanas de edad. La reducción de la PA mediante el tratamiento crónico con valsartán (60mg/Kg/día,p.o.) revirtió las desregulación de la AM y los componentes de su receptor, observados en las ratas SHR. El papel de las especies reactivas de oxígeno (EROS) en la acción de la AM cerebelosa quedó evidenciado, ya que la AM fue capaz de reducir la actividad de las tres enzimas antioxidantes, superóxiodo dismutasa (SOD), catalasa (CAT) y glutatión peroxidasa (GPx), en las ratas WKY y Sprague - Dawley (SD). Aún mas, nuestros hallazgos mostraron claramente el efecto antagónico entre la AM y la ANG II sobre la actividad de las enzimas antioxidantes inducida por la ANG II. El efecto de la AM sobre las enzimas antioxidantes no se manifestó en la ratas hipertensas, sin embargo el mismo fue restaurado mediante la disminución de la presión arterial con la administración crónica de dos antihipertensivos de mecanismo de acción distintos como la amlodipina (5mg/Kg/día,p.o) o el valsartán (60mg/Kg/día,p.o), lo que sugiere una relación entre la hipertensión y ausencia del efecto de AM en la ratas SHR. Al evaluar la posible vía de señalización que media la acción de la AM y el antagonismo con la ANG II sobre la actividad de las enzimas antioxidantes, demostramos que no existe una vía final común para dicho antagonismo, siendo la proteína quinasa A (PKA) y los 3 subtipos de receptores CGRP1, AM1 y AM2 los que median la acción de la AM, mientras que la acción de la ANG II se encuentra mediada a través de una vía que involucra la PKC/NAD(P)H oxidasa. Los hallazgos demuestran el antagonismo entre la AM y la ANG II en la regulación del estrés oxidativo en el cerebelo y ratifican la desregulación de la señalización de la AM mediada por EROs durante la hipertensión. Al evaluar las vías de señalización intracelular que median la acción de la AM en el cerebelo, demostramos que la AM es capaz de activar a las ERK, la producción de GMPc y NO a través de la estimulación del receptor AM1, y del AMPc a través de los tres subtipos de receptores de AM, lo que apoya que en el cerebelo la AM ejerce acciones a través de diversas vías de señalización como lo son NO/GMPc, AC/AMPc/PKA y/o ERK. El posible papel funcional de la AM in vivo fue inequívoco, ya que se demostró que la microinyección de AM en el vermis cerebeloso produjo una respuesta hipotensora profunda en las ratas SHR pero no en las normotensas. El hecho que la microinyección de AM en el vermis cerebelar en las ratas SD, WKY y SHR disminuyó significativamente la respuesta presora frente al estrés simpatoadrenal inducido por el estímulo eléctrico plantar, sugiere que la acción hipotensora está mediada a través de la regulación del eflujo simpático e indica un posible papel de la AM en la regulación de la respuesta CDV frente al estrés. En conjunto, nuestros resultados demuestran la existencia de un sistema adrenomedulinérgico funcional en el cerebelo, e indican por primera vez, que la AM cumple un papel importante en la regulación de la PA durante la hipertensión y el estrés.


Subject(s)
Animals , Male , Rats , Adrenomedullin/metabolism , Arterial Pressure/physiology , Cerebellar Vermis/metabolism , Hypertension/metabolism , Rats, Inbred SHR , Rats, Inbred WKY , Time Factors , Vasoconstrictor Agents/administration & dosage , Angiotensin II/administration & dosage , Blotting, Western , Rats, Sprague-Dawley , Amlodipine/administration & dosage , Oxidative Stress , Models, Animal , Adrenomedullin/administration & dosage , Receptors, Adrenomedullin/metabolism , Arterial Pressure/drug effects , Cerebellar Vermis/drug effects , Cerebellar Vermis/enzymology , Valsartan/administration & dosage , Antihypertensive Agents/administration & dosage
11.
Article in Spanish | LILACS | ID: lil-733434

ABSTRACT

La malaria es una enfermedad causada por parásitos del género Plasmodium estos parásitos tienen un ciclo intraeritocítico en el hospedador vertevrado. En el glóbulo rojo, el parásito ingiere la hemoglobina, obteniendo aminácidos y formando hemozoína. La hemozoína es un un material microcristalino oscuro, de color marrón amarillento, insoluble en agua, no tóxico, producido en la vacuola parasitófora del Plasmodium; este compuesto producido por el Plasmodium carece de la toxicidad que tiene el grupo hemo para el parásito. Asimismo se ha evidenciado que la hemozoína es una sustancia inmuno moduladora que tiene diversos efectos, como mediar la activación y migración de neutrófilos, incrementar la producción de óxido nítrico, inducir la activación de mataloproteínas 9, inducir la secreción de diferentes mediadores proinflamatorios, alterar las funciones de los monocitos y macrófagos humanos, tales como el estallido oxidativo, eliminación de bacterias, presentación de antígenos y la habilidad de diferenciarse a células dendríticas funcionales; por lo que la hemozína tiene efectos duales, tanto activadores como supresores de la respuesta inmune. Asimismo, la hemozoína es unblanco terapéutico potente, ya que los fármacos que inhiban su formación provocan toxicidad al parasíto e incluso la muerte del mismo.


Malaria is a disease caused by parasites of the genus Plasmodium. These parasites have intraerythrocytic cycle in the vertbrate host. In the red cell, the parasite ingests hemoglobin, obtaining amino acids and formin hemozoin. The microcrystaline material hemozoin is a dark, yellowish brown, insoluble in water, nontoxic, produced in the Plasmodium parasitophorous vacuole, this compound produced by Plasmodiun lacks the toxicity that has heme to the parasite. It has also been shown that hemozoin is an immune modulating substance that has different ffects, mediating the neutrophils activation and migration, increased nitric oxide production, induce activation of metallproteinase-9, induce the secretion of various proinflammatory mediators, alter the funcions of human monocytes and macrophages such as oxidative burst, removing bacteria, antigen presentation and the ability to differentiate into functional dendritic cells, so the hemozoin has dual effects, both activators and suppressors of the immune response. Also, the hemozoin is a potent therapeutic target, since rugs that inhibit their formation causes toxicity to the parasite and even death itself.


Subject(s)
Humans , Male , Female , Heme/analysis , Heme/biosynthesis , Malaria/diagnosis , Malaria/blood , Plasmodium/enzymology , Plasmodium/chemistry , Blood Chemical Analysis , Hematology , Hemoglobin A , Hemin/analysis , Parasitology
12.
Acta cient. Soc. Venez. Bioanalistas Esp ; 11(1): 30-36, 2008. ilus, tab
Article in Spanish | LILACS | ID: lil-733441

ABSTRACT

El estrés oxidativo juega un papel muy importante en la aterosclerosis; de hecho existe evidencias que indican que los antioxidantes son moléculas capaces de retardar y/o revertir el proceso aterosclerótico. El objetivo del presente estudio fue comparar el efecto de la vitamina C (Vit C), sobre la actividad de la Glutation peroxidasa (GPx) y la formación de ateromas en conejos. Se estudiaron 36 conejos divididos en 3 grupos: Grupo 1 (Control): conejarina, Grupo 2: huevo y conejarina, Grupo 3: huevo, conejarina y Vit C (100mg/diarios). el período experimental duró 12 semanas. Se determinó perfil lipídico por métodos enzimáticos y la actividad de GPx por cinética en 0 y 12va semana. Los conejos fueron sacrificados y se les realizó estudio histológico de su aorta. Los resultados revelaron un incremento en la actividad de la GPx en los grupos 2 y 3 con respecto al control en la 12va semana de experimentación (p<0,05). Hubo inhibición de lesiones ateroscleróticas en los conejos del grupo 3. En conclusión en condiciones de hiperlipidemia con o sin suplementación de Vit C, existe incremento en la actividad de GPx. Por otra parte, la Vit C disminuye y evita la progresión de ateromas.


Oxidative stress plays an important role in artherosclerosis; so antioxidants are molecules have been used to slow down or inihibit atherosclerosis. The objetive of the presents study was to compare the effect of Vitamin C (Vit C), on serum Glutathione peroxidase activity (GPx) and on the formation of aortic lesions in rabbits. 36 rabbits were studied: Group 1: "conejarina" (commercial rrabit food); Group 2: egg and conejarina, Group 3: egg, conejarina and Vit C (100mg/day). The experimental lasted 12 weeks. Lipid profile was done by enzymatic methods and GPx by kinetic method in weeks 0 and 12. Histological study of rabbit's aorta was done. GPx activity in groups 2 and 3, increased compared with controls, from weeks 12 of experimentation (o<0,05). There was inihition of aortic lesions in groups 3. In conclusion, under hyperlipidemic conditions, with or without Vit C supplementation, activity of GPx there is increase. Vit C reduces and prevents the progression of atheromas.


Subject(s)
Rabbits , Ascorbic Acid/administration & dosage , Ascorbic Acid/metabolism , Arteries/chemistry , Atherosclerosis/genetics , Atherosclerosis/blood , Glutathione Peroxidase/biosynthesis , Glutathione Peroxidase/chemistry , Free Radicals/chemistry , Blood Chemical Analysis , Hematology
13.
Acta cient. Soc. Venez. Bioanalistas Esp ; 10(2): 86-90, 2007. ilus, tab
Article in Spanish | LILACS | ID: lil-733460

ABSTRACT

La Mieloperoxidasa (MPO) y la Proteína C Reactiva (PCR) han sido implicados en la fisiopatología de la aterosclerosis. El objetivo del presente estudio fue determinar las concentraciones plasmáticas de MPO y PCR y su relación con la formación de ateromas en conejos. Se estudiaron 23 conejos machos Nueva Zelanda: Grupo 1: conejarina y verdura; Grupo 2: Huevo y conejarina. El periodo experimental duró 13 semanas. Se determinó perfil lipídico por métodos enzimáticos, MPO por ELISA y PCR por turbidimetría en 0 13va semana. Se realizó estudio histológico de aorta. Los resultados revelaron que la PCR se elevó en el grupo 2 al final del estudio (p<0,05). No se observó diferencias en MPO en el grupo 2 en el estudio. En cuanto a los ateromas se evidenciaron lesiones tipo I y II en los conejos del grupo 2. En conclusión, se encontró que la PCR y no la MPO son marcadores de aterosclerosis según nuestras condiciones experimentales.


Myeloperoxidase (MPO) and C-reactive protein (CRP) have been implicated in atherosclerosis. The objective of the present study was to determine plasma concentration MPO and CRP and its relationship of formation of aortic lesions in rabbits. 23 male New Zealand rabbits were study: Group 1: “conejarina” (commercial rabbit food) and vegetables; Group 2: egg and conejarina. The experiment lasted 13 weeks. Lipid profile was done by enzymatic methods, MPO by ELISA, and PCR by turbidimetry in weeks 0 and 13. Histological study of rabbits’ aorta was done. Results revealed that in group 2 CRP increased at final study (p <0.05). No differences were observed in MPO values in the experiment. Regarding atheroma, group 2 presented type I and II lesions. In conclusion only CRP is marker of atherosclerosis according to our experimental conditions.


Subject(s)
Male , Animals , Rabbits , Atherosclerosis , Diet, High-Fat/methods , Oxidation , Peroxidase/analysis , Peroxidase/blood , C-Reactive Protein/analysis , Plasma Volume/radiation effects , Plasma Volume/physiology , Plasma Volume/veterinary
14.
Article in Spanish | LILACS | ID: lil-733462

ABSTRACT

La inflamación tiene un papel establecido, tanto en la iniciación como en la progresión del proceso aterosclerótico y el síndrome coronario agudo. Factores de transcripción nuclear, macrófagos y linfocitos participan y modulan los mecanismos inflamatorios asociados con la rotura o la erosión de la placa, que culmina en muchos casos con el síndrome coronario agudo. Estas biomoléculas constituyen objetivos de medición para tratar de identificar y monitorizar el infarto agudo al miocardio. La lista de biomarcadores estudiados en la enfermedad cardiovascular se ha expandido rápidamente en los últimos tiempos. El presente artículo consiste en una revisión de los biomarcadores de lesión miocárdica frecuentemente utilizados, así como su poder predictor de enfermedad coronaria.


It‘s well-known that inflammation plays a role in atherogenesis, atherosclerotic plaque progression, and acute coronary syndrome. Nuclear transcription Factors, macrophagues and lymphocyte, participate and modulate the inflammatory mechanisms associate with the breakage or the erosion of the plate, that culminates in many causes with the acute coronary syndrome. These biomolecules constitute measurement objectives to try, identify and to monitorear the acute infarct to the myocardium. The list of biomarkers studied in the cardiovascular disease has expanded quickly lately. The present article consists in a review of the biomarkers of myocardic leasures frequently used as a power predictor for coronary disease.


Subject(s)
Humans , Coronary Disease/prevention & control , Coronary Artery Disease/physiopathology , Myocardial Infarction/physiopathology , Biomarkers , Cardiology , Hematology
15.
Salus ; 8(3): 33-40, dic. 2004.
Article in Spanish | LILACS | ID: lil-502711

ABSTRACT

La Diabetes Mellitus es un síndrome crónico producido por una deficiencia de insulina o por una insensibilidad de los tejidos periféricos. Actualmente se conoce que es una enfermedad que incide con mayor frecuencia en personas mayores de 40 años. A fin de establecer la relación que puede existir entre los niveles séricos de Homocisteína con parámetros urinarios del funcionalismo renal (Depuración de Creatinina, Microalbúminuria y β2 Microglobulina) se estudiaron los pacientes DM2 que acudieron a la Unidad de Diabetes de la CHET. La muestra estuvo constituida por 50 pacientes con más de cinco años de evolución de la enfermedad y 24 sujetos aparentemente sanos de ambos géneros (controles). Se determinaron los niveles séricos de homocisteína por inmunoensayo de polarización de la fluorescencia y los parámetros urinarios fueron realizados en orinas de 24 horas por métodos nefelométricos y colorimetricos. La creatina por la reacción de Jaffe y la hemoglobina glicosilada A1c por cromatografía. En cuanto a los resultados, se obtuvieron las siguientes cifras promedios: Glicemia: 198,3 ± 97,4 mg/dL, β2 Microglobulina: 0,2182 ± 0,1319 mg/L, Microalbúminuria 20,14 ± 20,45 mg/L, Hb-glicosilada A1c: 7,653 ± 2,019 por ciento, Homocisteína: 8,444 ± 2,081 μmol/L. Se concluye que aunque los valores de homocisteína séricos estuvieron dentro del rango normal, esta puede jugar un papel importante en el daño renal, en los pacientes (DM2) a través del tiempo


Subject(s)
Humans , Male , Female , Urinary Bladder Diseases , Homocysteine , Biomarkers , Renal Artery Obstruction , Endocrinology , Internal Medicine , Urology , Venezuela
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