RESUMEN

Lactate modulates the expression of lactate oxidation complex (LOC)-related genes and cardiac blood flow under physiological conditions, but its modulatory role remains to be elucidated regarding pathological cardiac stress. The present study evaluated the effect of lactate on LOC-related genes expression and hemodynamics of hearts submitted to myocardial infarction (MI). Four weeks after MI or sham operation, isolated hearts of male Wistar rats were perfused for 60 min with Na+-lactate (20 mM). As expected, MI reduced cardiac contractility and relaxation with no changes in perfusion. The impaired cardiac hemodynamics were associated with increased reactive oxygen species (ROS) levels (Sham: 19.3±0.5 vs MI: 23.8±0.3 µM), NADPH oxidase (NOX) activity (Sham: 42.2±1.3 vs MI: 60.5±1.5 nmol·h-1·mg-1) and monocarboxylate transporter 1 (mct1) mRNA levels (Sham: 1.0±0.06 vs MI: 1.7±0.2 a.u.), but no changes in superoxide dismutase (SOD), catalase, NADH oxidase (NADox), and xanthine oxidase activities. Lactate perfusion in MI hearts had no additional effect on ROS levels, NADox, and NOX activity, however, it partially reduced mct1 mRNA expression (MI-Lactate 1.3±0.08 a.u.). Interestingly, lactate significantly decreased SOD (MI-Lactate: 54.5±4.2 µmol·mg-1·min-1) and catalase (MI: 1.1±0.1 nmol·mg-1·min-1) activities in MI. Collectively, our data suggest that under pathological stress, lactate lacks its ability to modulate the expression of cardiac LOC-related genes and the perfused pressure in hearts submitted to chronic MI. Together, these data contribute to elucidate the mechanisms involved in the pathogenesis of heart failure induced by MI.

Asunto(s)

Ventrículos Cardíacos/efectos de los fármacos , Ventrículos Cardíacos/metabolismo , Ácido Láctico/metabolismo , Ácido Láctico/farmacología , Infarto del Miocardio/genética , Infarto del Miocardio/metabolismo , Animales , Catalasa/análisis , Expresión Génica , Ácido Láctico/análisis , Masculino , Complejos Multienzimáticos/análisis , NADH NADPH Oxidorreductasas/análisis , NADPH Oxidasas/análisis , Oxidación-Reducción/efectos de los fármacos , Perfusión , Ratas Wistar , Reacción en Cadena en Tiempo Real de la Polimerasa , Valores de Referencia , Superóxido Dismutasa/análisis , Factores de Tiempo , Regulación hacia Arriba/efectos de los fármacos , Xantina Oxidasa/análisis

RESUMEN

Lactate modulates the expression of lactate oxidation complex (LOC)-related genes and cardiac blood flow under physiological conditions, but its modulatory role remains to be elucidated regarding pathological cardiac stress. The present study evaluated the effect of lactate on LOC-related genes expression and hemodynamics of hearts submitted to myocardial infarction (MI). Four weeks after MI or sham operation, isolated hearts of male Wistar rats were perfused for 60 min with Na+-lactate (20 mM). As expected, MI reduced cardiac contractility and relaxation with no changes in perfusion. The impaired cardiac hemodynamics were associated with increased reactive oxygen species (ROS) levels (Sham: 19.3±0.5 vs MI: 23.8±0.3 µM), NADPH oxidase (NOX) activity (Sham: 42.2±1.3 vs MI: 60.5±1.5 nmol·h−1·mg−1) and monocarboxylate transporter 1 (mct1) mRNA levels (Sham: 1.0±0.06 vs MI: 1.7±0.2 a.u.), but no changes in superoxide dismutase (SOD), catalase, NADH oxidase (NADox), and xanthine oxidase activities. Lactate perfusion in MI hearts had no additional effect on ROS levels, NADox, and NOX activity, however, it partially reduced mct1 mRNA expression (MI-Lactate 1.3±0.08 a.u.). Interestingly, lactate significantly decreased SOD (MI-Lactate: 54.5±4.2 µmol·mg−1·min−1) and catalase (MI: 1.1±0.1 nmol·mg−1·min−1) activities in MI. Collectively, our data suggest that under pathological stress, lactate lacks its ability to modulate the expression of cardiac LOC-related genes and the perfused pressure in hearts submitted to chronic MI. Together, these data contribute to elucidate the mechanisms involved in the pathogenesis of heart failure induced by MI.

Asunto(s)

Animales , Masculino , Ácido Láctico/metabolismo , Ácido Láctico/farmacología , Ventrículos Cardíacos/efectos de los fármacos , Ventrículos Cardíacos/metabolismo , Infarto del Miocardio/genética , Infarto del Miocardio/metabolismo , Perfusión , Factores de Tiempo , Catalasa/análisis , Expresión Génica , Ratas Wistar , Ácido Láctico/análisis , Complejos Multienzimáticos/análisis , NADH NADPH Oxidorreductasas/análisis

RESUMEN

Avaliou-se o efeito do ambiente ruminal sobre a degradação da FDN de 12 cultivares de cana. As dietas continham: 87,1% de cana (Cana) ou 42,0% de cana e 58,0% de concentrado com milho (Milho) ou polpa cítrica (Polpa). Seis vacas com cânula ruminal formaram quadrados latinos 3x3. Por 11 dias de cada período experimental, o consumo de matéria seca foi fixado em 1,2% do peso vivo. No dia 12, baixo pH ruminal foi induzido no Milho e na Polpa por infusão intrarruminal de milho ou polpa cítrica. Simultaneamente, ureia foi adicionada ao rúmen em todos os tratamentos. Sacos de náilon contendo os cultivares foram incubados por 24h nos dias 11 e 12. O pH ruminal no dia 11 foi 7,01 e NH3 foi 3,4, 4,4 e 6,2mg/dL para Cana, Milho e Polpa, respectivamente. O pH no dia 12 foi 6,98 para Cana, 6,49 para Milho e 6,04 para Polpa, e NH3 foi 13,0mg/dL. Para Cana, a degradabilidade ruminal da FDN foi 21% no dia 11 e 28% no dia 12; para Milho e Polpa esta foi ao redor de 21% em ambos os dias. O ordenamento dos cultivares por degradabilidade ruminal da FDN foi similar nos ambientes ruminais distintos.(AU)

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The effect of the rumen environment on NDF degradability of 12 sugarcane cultivars was evaluated. Diets contained: 87.1% of sugarcane (Cane) or 42.0% of sugarcane and 58.0% of concentrates with corn (Corn) or citrus pulp (Citrus). Six rumen cannulated cows formed 3x3 Latin Squares. For 11 days of each experimental period, the intake of dry matter was fixed at 1.2% of body weight. On day 12, low ruminal pH was induced on Corn and Citrus by pulse dosing corn or citrus pulp into the rumen. Simultaneously, urea was added to the rumen in all treatments. Nylon bags containing the cultivars were incubated for 24 h on the 11th and 12th days. Rumen pH on day 11 was 7.01 and NH3 was 3.4, 4.4 and 6.2 mg/dl for Cane, Corn and Citrus, respectively. Ruminal pH on day 12 was 6.98 for Cane, 6.49 for Corn and 6.04 for Citrus and NH3 was 13.0 mg/dl. For Cane, ruminal NDF degradability was 21% on day 11 and 28% on day 12, for Corn and Citrus it was around 21% in both days. The ranking of cultivars based on ruminal NDF degradability was similar in distinct rumen environments.(AU)

Asunto(s)

Animales , Bovinos , Rumen , Saccharum/efectos adversos , Almidón/efectos adversos , Digestión , Fibras de la Dieta , Citrus/efectos adversos , Alimentación Animal/efectos adversos , Alimentación Animal/análisis , Tracto Gastrointestinal

RESUMEN

Avaliou-se o efeito do ambiente ruminal sobre a degradação da FDN de 12 cultivares de cana. As dietas continham: 87,1% de cana (Cana) ou 42,0% de cana e 58,0% de concentrado com milho (Milho) ou polpa cítrica (Polpa). Seis vacas com cânula ruminal formaram quadrados latinos 3x3. Por 11 dias de cada período experimental, o consumo de matéria seca foi fixado em 1,2% do peso vivo. No dia 12, baixo pH ruminal foi induzido no Milho e na Polpa por infusão intrarruminal de milho ou polpa cítrica. Simultaneamente, ureia foi adicionada ao rúmen em todos os tratamentos. Sacos de náilon contendo os cultivares foram incubados por 24h nos dias 11 e 12. O pH ruminal no dia 11 foi 7,01 e NH3 foi 3,4, 4,4 e 6,2mg/dL para Cana, Milho e Polpa, respectivamente. O pH no dia 12 foi 6,98 para Cana, 6,49 para Milho e 6,04 para Polpa, e NH3 foi 13,0mg/dL. Para Cana, a degradabilidade ruminal da FDN foi 21% no dia 11 e 28% no dia 12; para Milho e Polpa esta foi ao redor de 21% em ambos os dias. O ordenamento dos cultivares por degradabilidade ruminal da FDN foi similar nos ambientes ruminais distintos.(AU)

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The effect of the rumen environment on NDF degradability of 12 sugarcane cultivars was evaluated. Diets contained: 87.1% of sugarcane (Cane) or 42.0% of sugarcane and 58.0% of concentrates with corn (Corn) or citrus pulp (Citrus). Six rumen cannulated cows formed 3x3 Latin Squares. For 11 days of each experimental period, the intake of dry matter was fixed at 1.2% of body weight. On day 12, low ruminal pH was induced on Corn and Citrus by pulse dosing corn or citrus pulp into the rumen. Simultaneously, urea was added to the rumen in all treatments. Nylon bags containing the cultivars were incubated for 24 h on the 11th and 12th days. Rumen pH on day 11 was 7.01 and NH3 was 3.4, 4.4 and 6.2 mg/dl for Cane, Corn and Citrus, respectively. Ruminal pH on day 12 was 6.98 for Cane, 6.49 for Corn and 6.04 for Citrus and NH3 was 13.0 mg/dl. For Cane, ruminal NDF degradability was 21% on day 11 and 28% on day 12, for Corn and Citrus it was around 21% in both days. The ranking of cultivars based on ruminal NDF degradability was similar in distinct rumen environments.(AU)

Asunto(s)

Animales , Femenino , Bovinos , Rumen/química , Saccharum/química , Rumiación Digestiva , Alimentación Animal/análisis

RESUMEN

Objetivou-se avaliar a variabilidade do valor nutritivo entre cultivares de cana-de-açúcar, estimar a correlação entre digestibilidade e produtividade da planta e definir características químicas e agronômicas mais correlacionadas ao valor nutritivo. Vinte cultivares de cana-de-açúcar foram cultivados em delineamento em blocos ao acaso, com quatro repetições, em Campos, RJ, Brasil. As plantas foram colhidas com Brix superior a 18 por cento, a partir de 370 dias do corte da segunda soca. Características agronômicas e químicas e as degradabilidades ruminais in situ da FDN e da MS foram avaliadas. A produtividade foi 21,2±5,7t de MS/ha, e a degradabilidade ruminal da MS (DEG MS) foi 57,1±2,6 por cento do incubado (média±DP). A degradabilidade ruminal da FDN foi 19,8±2,42 por cento do incubado. Nenhuma variável avaliada foi correlacionada à degradabilidade da FDN (P>0,10). Obter cultivares que conciliam alta produtividade com alta DEG MS é viável, pois a correlação tanto fenotípica quanto genética entre esses caracteres foi pequena. A h2 para a DEG MS foi superior a 85 por cento. Variáveis indiretamente correlacionadas à DEG MS tiveram menor h2 que o desta variável. Canas com baixo conteúdo de fibra, com colmos curtos e com alta relação entre colmos e folhas, foram mais digestíveis.(AU)

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The objective was to evaluate the variability of nutritive value among sugarcane cultivars, to estimate the correlation between plant digestibility and productivity, and to define agronomical and chemical traits most correlated with nutritive value. Twenty sugarcane cultivars were cultivated in a completely randomized block design with four replicates in Campos, RJ, Brazil. Plants were harvested when the Brix was superior to 18 percent, starting at 370 days after the second ratoon cut. Agronomical and chemical traits and the ruminal NDF and DM in situ degradability were evaluated. Productivity was 21.2±5.7t of DM/ha and ruminal DM degradability (DM DEG) was 57.1±2.6 percent of incubated (mean±SD). Ruminal NDF degradability was 19.8±2.42 percent of incubated, and none of the variables evaluated were correlated to the NDF degradability (P>0.10). Obtaining cultivars that conciliate high productivity to high digestibility is feasible, since the phenotypic and the genetic correlation between these traits were low. The estimated h2 for the DM DEG was superior to 85 percent. Variables indirectly correlated to the digestibility had smaller h2 than the one for this variable. Sugarcane with low fiber content, short stalk length and high stalk to leaves ratio were more digestible.(AU)

Asunto(s)

Animales , Bovinos , Bovinos/fisiología , Saccharum/química , Saccharum/crecimiento & desarrollo , Alimentación Animal , Fenómenos Fisiológicos Nutricionales de los Animales/fisiología , Fibras de la Dieta , Nutrientes

RESUMEN

Objetivou-se avaliar a variabilidade do valor nutritivo entre cultivares de cana-de-açúcar, estimar a correlação entre digestibilidade e produtividade da planta e definir características químicas e agronômicas mais correlacionadas ao valor nutritivo. Vinte cultivares de cana-de-açúcar foram cultivados em delineamento em blocos ao acaso, com quatro repetições, em Campos, RJ, Brasil. As plantas foram colhidas com Brix superior a 18 por cento, a partir de 370 dias do corte da segunda soca. Características agronômicas e químicas e as degradabilidades ruminais in situ da FDN e da MS foram avaliadas. A produtividade foi 21,2±5,7t de MS/ha, e a degradabilidade ruminal da MS (DEG MS) foi 57,1±2,6 por cento do incubado (média±DP). A degradabilidade ruminal da FDN foi 19,8±2,42 por cento do incubado. Nenhuma variável avaliada foi correlacionada à degradabilidade da FDN (P>0,10). Obter cultivares que conciliam alta produtividade com alta DEG MS é viável, pois a correlação tanto fenotípica quanto genética entre esses caracteres foi pequena. A h2 para a DEG MS foi superior a 85 por cento. Variáveis indiretamente correlacionadas à DEG MS tiveram menor h2 que o desta variável. Canas com baixo conteúdo de fibra, com colmos curtos e com alta relação entre colmos e folhas, foram mais digestíveis...

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The objective was to evaluate the variability of nutritive value among sugarcane cultivars, to estimate the correlation between plant digestibility and productivity, and to define agronomical and chemical traits most correlated with nutritive value. Twenty sugarcane cultivars were cultivated in a completely randomized block design with four replicates in Campos, RJ, Brazil. Plants were harvested when the Brix was superior to 18 percent, starting at 370 days after the second ratoon cut. Agronomical and chemical traits and the ruminal NDF and DM in situ degradability were evaluated. Productivity was 21.2±5.7t of DM/ha and ruminal DM degradability (DM DEG) was 57.1±2.6 percent of incubated (mean±SD). Ruminal NDF degradability was 19.8±2.42 percent of incubated, and none of the variables evaluated were correlated to the NDF degradability (P>0.10). Obtaining cultivars that conciliate high productivity to high digestibility is feasible, since the phenotypic and the genetic correlation between these traits were low. The estimated h2 for the DM DEG was superior to 85 percent. Variables indirectly correlated to the digestibility had smaller h2 than the one for this variable. Sugarcane with low fiber content, short stalk length and high stalk to leaves ratio were more digestible...

Asunto(s)

Animales , Bovinos , Alimentación Animal , Bovinos/fisiología , Fenómenos Fisiológicos Nutricionales de los Animales/fisiología , Saccharum/crecimiento & desarrollo , Saccharum/química , Fibras de la Dieta , Nutrientes

RESUMEN

The objective of the present study was to evaluate memory performance in tasks with and without affective content (to confirm the mood congruency phenomenon) in acutely admitted patients with bipolar I disorder (BD) and major depression disorder (MDD) and in healthy participants. Seventy-eight participants (24 BD, 29 MDD, and 25 healthy controls) were evaluated. Three word lists were used as the memory task with affective content (positive, negative and indifferent). Psychiatric symptoms were also evaluated with rating scales (Young Mania Rating Scale for mania and Hamilton Depression Rating Scale for depression). Patients were selected during the first week of hospitalization. BD patients showed higher scores in the word span with positive tone than MDD patients and healthy controls (P = 0.002). No other difference was observed for tests with affective tone. MDD patients presented significantly lower scores in the Mini-Mental State Exam, logical memory test, visual recognition span, and digit span, while BD patients presented lower scores in the visual recognition test and digit span. Mood congruency effect was found for word span with positive tone among BD patients but no similar effect was observed among MDD patients for negative items. MDD patients presented more memory impairment than BD patients, but BD patients also showed memory impairment.

Asunto(s)

Adulto , Femenino , Humanos , Masculino , Persona de Mediana Edad , Trastorno Bipolar/complicaciones , Trastorno Depresivo Mayor/complicaciones , Trastornos de la Memoria/etiología , Trastornos del Humor/etiología , Estudios de Casos y Controles , Estudios Transversales , Escolaridad , Trastornos de la Memoria/diagnóstico , Trastornos del Humor/diagnóstico , Pruebas Neuropsicológicas , Escalas de Valoración Psiquiátrica

RESUMEN

The objective of the present study was to evaluate memory performance in tasks with and without affective content (to confirm the mood congruency phenomenon) in acutely admitted patients with bipolar I disorder (BD) and major depression disorder (MDD) and in healthy participants. Seventy-eight participants (24 BD, 29 MDD, and 25 healthy controls) were evaluated. Three word lists were used as the memory task with affective content (positive, negative and indifferent). Psychiatric symptoms were also evaluated with rating scales (Young Mania Rating Scale for mania and Hamilton Depression Rating Scale for depression). Patients were selected during the first week of hospitalization. BD patients showed higher scores in the word span with positive tone than MDD patients and healthy controls (P = 0.002). No other difference was observed for tests with affective tone. MDD patients presented significantly lower scores in the Mini-Mental State Exam, logical memory test, visual recognition span, and digit span, while BD patients presented lower scores in the visual recognition test and digit span. Mood congruency effect was found for word span with positive tone among BD patients but no similar effect was observed among MDD patients for negative items. MDD patients presented more memory impairment than BD patients, but BD patients also showed memory impairment.

Asunto(s)

Trastorno Bipolar/complicaciones , Trastorno Depresivo Mayor/complicaciones , Trastornos de la Memoria/etiología , Trastornos del Humor/etiología , Adulto , Estudios de Casos y Controles , Estudios Transversales , Escolaridad , Femenino , Humanos , Masculino , Trastornos de la Memoria/diagnóstico , Persona de Mediana Edad , Trastornos del Humor/diagnóstico , Pruebas Neuropsicológicas , Escalas de Valoración Psiquiátrica

RESUMEN

The present cross-sectional study was designed to assess the frequency of 36 possible triggering factors precipitating a migraine crisis (hormonal, environmental, and dietary) in adult outpatients suffering from migraine attacks. A group of 123 migraine sufferers, aged 43.2 ± 13.9 (mean ± SD) years, including 114 (92.7%) women, 68.3% having migraine without aura, 68.3% reporting pain severe enough to require drug prophylaxis, and 29.3% presenting with hypertension, were evaluated. The most common triggers were stress and fasting, and environmental and hormonal factors were frequently found to precipitate a crisis. More than 90% of the patients reported susceptibility to 5 or more factors, and only 2.4% did not complain about any dietary factor. The large number of triggers detected in the present study emphasises the importance of awareness and avoidance of these factors in the management of patients with migraine.

Asunto(s)

Dieta , Trastornos Migrañosos/etiología , Adolescente , Adulto , Edad de Inicio , Anciano , Estudios Transversales , Ambiente , Etnicidad , Femenino , Hormonas/fisiología , Humanos , Masculino , Persona de Mediana Edad , Migraña con Aura/etiología , Migraña sin Aura/etiología , Factores Socioeconómicos , Adulto Joven

RESUMEN

Blood pressure variability (BPV) and baroreflex dysfunction may contribute to end-organ damage process. We investigated the effects of baroreceptor deficit (10 weeks after sinoaortic denervation - SAD) on hemodynamic alterations, cardiac and pulmonary remodeling. Cardiac function and morphology of male Wistar intact rats (C) and SAD rats (SAD) (n=8/group) were assessed by echocardiography and collagen quantification. BP was directly recorded. Ventricular hypertrophy was quantified by the ratio of left ventricular weight (LVW) and right ventricular weight (RVW) to body weight (BW). BPV was quantified in the time and frequency domains. The atrial natriuretic peptide (ANP), alpha-skeletal actin (α-skelectal), collagen type I and type III genes mRNA expression were evaluated by RT-PCR. SAD did not change BP, but increased BPV (11±0.49 vs. 5±0.3 mmHg). As expected, baroreflex was reduced in SAD. Pulmonary artery acceleration time was reduced in SAD. In addition, SAD impaired diastolic function in both LV (6.8±0.26 vs. 5.02±0.21 mmHg) and RV (5.1±0.21 vs. 4.2±0.12 mmHg). SAD increased LVW/BW in 9% and RVW/BW in 20%, and augmented total collagen (3.8-fold in LV, 2.7-fold in RV, and 3.35-fold in pulmonary artery). Also, SAD increased type I (~6-fold) and III (~5-fold) collagen gene expression. Denervation increased ANP expression in LV (75%), in RV (74%) and increased α-skelectal expression in LV (300%) and in RV (546%). Baroreflex function impairment by SAD, despite not changing BP, induced important adjustments in cardiac structure and pulmonary hypertension. These changes may indicate that isolated baroreflex dysfunction can modulate target tissue damage.

Asunto(s)

Barorreflejo/fisiología , Hipertensión Pulmonar/fisiopatología , Hipertrofia Ventricular Izquierda/fisiopatología , Presorreceptores/fisiopatología , Arteria Pulmonar/fisiopatología , Animales , Desnervación Autonómica/efectos adversos , Desnervación Autonómica/métodos , Modelos Animales de Enfermedad , Hipertensión Pulmonar Primaria Familiar , Ventrículos Cardíacos/diagnóstico por imagen , Ventrículos Cardíacos/patología , Ventrículos Cardíacos/fisiopatología , Hipertensión Pulmonar/etiología , Hipertensión Pulmonar/patología , Hipertrofia Ventricular Izquierda/etiología , Hipertrofia Ventricular Izquierda/patología , Masculino , Presorreceptores/lesiones , Presorreceptores/cirugía , Arteria Pulmonar/diagnóstico por imagen , Arteria Pulmonar/patología , Ratas , Ratas Wistar , Ultrasonografía

RESUMEN

Role of reactive oxygen species (ROS)/nitric oxide (NO) balance and renin-angiotensin system in mediating cardiac hypertrophy in hyperthyroidism was evaluated in an in vivo and in vitro experimental model. Male Wistar rats were divided into four groups: control, thyroid hormone, vitamin E (or Trolox, its hydrosoluble analogue), thyroid hormone+vitamin E. Angiotensin II receptor (AT1/AT2) gene expression, immunocontent of AT1/AT2 receptors, angiotensinogen, NADPH oxidase (Nox2), and nitric oxide synthase isoforms, as well as ROS concentration (hydrogen peroxide and superoxide anion) were quantified in myocardium. Thyroid hormone increased ROS and NO metabolites, iNOS, nNOS and eNOS isoforms and it was accompanied by cardiac hypertrophy. AT1/AT2 expression and the immunocontent of angiotensinogen and Nox2 were enhanced by thyroid hormone. Antioxidants reduced ROS levels, Nox2, AT1/AT2, NOS isoforms and cardiac hypertrophy. In conclusion, ROS/NO balance may play a role in the control of thyroid hormone-induced cardiac hypertrophy mediated by renin-angiotensin system.

Asunto(s)

Cardiomegalia/patología , Especies de Nitrógeno Reactivo/metabolismo , Especies Reactivas de Oxígeno/metabolismo , Sistema Renina-Angiotensina/fisiología , Hormonas Tiroideas/metabolismo , Angiotensinógeno/análisis , Animales , Western Blotting , Cardiomegalia/metabolismo , Células Cultivadas , Cromanos/farmacología , Hipertiroidismo/metabolismo , Masculino , NADPH Oxidasas/análisis , Óxido Nítrico/análisis , Óxido Nítrico Sintasa/genética , Reacción en Cadena de la Polimerasa , Ratas , Ratas Wistar , Receptor de Angiotensina Tipo 1/genética , Receptor de Angiotensina Tipo 1/metabolismo , Receptor de Angiotensina Tipo 2/genética , Receptor de Angiotensina Tipo 2/metabolismo , Receptores de Angiotensina/genética , Hormonas Tiroideas/farmacología , Vitamina E/farmacología

RESUMEN

Primary cultures of vascular smooth muscle cells (VSMCs) from rats offer a good model system to examine the molecular basis of mechanism of vascular contraction-relaxation. However, during pathological conditions such as atherosclerosis and hypertension, VSMCs characteristically exhibit phenotypic modulation, change from a quiescent contractile to a proliferative synthetic phenotype, which impairs this mechanism of vascular contraction-relaxation. Taking in account that Myosin light chain (MLC) and ERK1/2 directly participate in the process of vascular contraction, the aim of the current study was to analyze the involvement of MLC and ERK1/2 signaling during the process of VSMCs phenotypic modulation. Primary cultures of VSMCs from rat thoracic aortas were isolated and submitted to different number of passages or to freezing condition. Semi-quantitative RT-PCR was used to evaluate the mRNA levels of VSMCs differentiation markers, and western blot assays were used to determine the MLC and ERK1/2 phosphorylation levels during VSMCs phenotypic modulation. Also, immunocytochemical experiments were performed to evaluate morphological alterations occurred during the phenotypic modulation. Elevated number of passages (up to 4) as well as the freezing/thawing process induced a significant phenotypic modulation in VSMCs, which was accompanied by diminished MLC and ERK1/2 phosphorylation levels. Phosphorylation of MLC was suppressed completely by the treatment with a synthetic inhibitor of MEK-1, a direct upstream of ERK1/2, PD98059. These findings provide that ERK1/2-promoted MLC phosphorylation is impaired during VSMCs phenotypic modulation, suggesting that ERK1/2 signaling pathway may represent a potential target for understanding the pathogenesis of several vascular disease processes frequently associated to this condition.

Asunto(s)

Proteína Quinasa 3 Activada por Mitógenos/fisiología , Músculo Liso Vascular/citología , Cadenas Ligeras de Miosina/fisiología , Transducción de Señal , Animales , Aorta , Diferenciación Celular , Células Cultivadas , Proteína Quinasa 3 Activada por Mitógenos/metabolismo , Músculo Liso Vascular/metabolismo , Músculo Liso Vascular/fisiología , Fenotipo , Fosforilación , Ratas , Vasoconstricción , Vasodilatación

RESUMEN

Although most of effects of Angiotensin II (Ang II) related to cardiac remodelling can be attributed to type 1 Ang II receptor (AT(1)R), the type 2 receptor (AT(2)R) has been shown to be involved in the development of some cardiac hypertrophy models. In the present study, we investigated whether the thyroid hormone (TH) action leading to cardiac hypertrophy is also mediated by increased Ang II levels or by change on AT(1)R and AT(2)R expression, which could contribute to this effect. In addition, we also evaluated the possible contribution of AT(2)R in the activation of Akt and in the development of TH-induced cardiac hypertrophy. To address these questions, Wistar rats were treated with thyroxine (T(4), 0.1 mg/kg BW/day, i.p.), with or without AT(2)R blocker (PD123319), for 14 days. Cardiac hypertrophy was identified based on heart/body weight ratio and confirmed by analysis of atrial natriuretic factor mRNA expression. Cardiomyocyte cultures were used to exclude the influence of TH-related hemodynamic effects. Our results demonstrate that the cardiac Ang II levels were significantly increased (80%, P < 0.001) as well as the AT(2)R expression (50%, P < 0.05) in TH-induced cardiac hypertrophy. The critical involvement of AT(2)R to the development of this cardiac hypertrophy in vivo was evidenced after administration of AT(2) blocker, which was able to prevent in 40% (P < 0.01) the cardiac mass gain and the Akt activation induced by TH. The role of AT(2)R to the TH-induced cardiomyocyte hypertrophy was also confirmed after using PD123319 in the in vitro studies. These findings improve understanding of the cardiac hypertrophy observed in hyperthyroidism and provide new insights into the generation of future therapeutic strategies.

Asunto(s)

Bloqueadores del Receptor Tipo 2 de Angiotensina II , Cardiopatías/inducido químicamente , Cardiopatías/prevención & control , Miocardio/patología , Proteínas Proto-Oncogénicas c-akt/antagonistas & inhibidores , Tiroxina/efectos adversos , Angiotensina II/fisiología , Animales , Células Cultivadas , Modelos Animales de Enfermedad , Cardiopatías/fisiopatología , Hipertiroidismo/fisiopatología , Hipertrofia/inducido químicamente , Hipertrofia/fisiopatología , Hipertrofia/prevención & control , Imidazoles/farmacología , Miocitos Cardíacos/efectos de los fármacos , Miocitos Cardíacos/patología , Proteínas Proto-Oncogénicas c-akt/fisiología , Piridinas/farmacología , Ratas , Ratas Wistar , Receptor de Angiotensina Tipo 1/fisiología , Receptor de Angiotensina Tipo 2/fisiología , Transducción de Señal/fisiología

RESUMEN

Avaliaram-se o desempenho e a eficiência financeira de vacas leiteiras alimentadas com dietas com substituição total de milho por polpa cítrica. O teor dietético do milho foi 10 por cento e o de polpa 24 por cento nos tratamentos com milho, e o de polpa foi 33 por cento nas dietas exclusivas com polpa. A substituição total das fontes inorgânicas Cu, Mn, Se, Zn e Cr por fontes orgânicas foi avaliada simultaneamente. As quatro dietas geradas por arranjo fatorial dos dois fatores foram fornecidas a 16 vacas em Quadrado Latino 4x4. As produções de leite foram 27,5kg para vacas alimentadas com polpa e 28,4kg para aquelas que receberam milho (P=0,04). A substituição total de milho por polpa cítrica reduziu o teor e a produção de proteína no leite (P<0,03), e não afetou a secreção de gordura (P>0,24). Dietas formuladas exclusivamente com polpa cítrica podem ser indicadas quando o pagamento do leite for baseado apenas no volume. A inclusão de milho pode aumentar a renda bruta subtraída do custo alimentar quando a produção de sólidos for valorizada.(AU)

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The performance and financial efficiency of dairy cows fed diets formulated by total replacement of corn by citrus pulp was evaluated. Treatments with corn contained 10 percent corn and 24 percent citrus pulp while citrus diets contained 33 percent citrus pulp. The complete replacement of inorganic sources of Cu, Mn, Se, Zn, and Cr by organic sources was simultaneously evaluated. The four diets generated by the factorial arrangement of the two factors were fed to 16 cows in 4x4 Latin Squares. Means of milk production were 27.5kg and 28.4kg for cows fed citrus pulp and corn (P=0.04) diets, respectively. The complete replacement of corn by citrus pulp decreased milk protein production and content (P<0.03) and had no effect on milk fat (P>0.24). Diets formulated exclusively with citrus pulp may be recommended when milk payment is based exclusively on volume, but the inclusion of corn may increase income over feed cost when milk solids are valued.(AU)

Asunto(s)

Animales , Femenino , Zea mays/efectos adversos , Citrus/efectos adversos , Producción de Alimentos , Economía de los Alimentos , Bovinos

RESUMEN

Avaliaram-se o desempenho e a eficiência financeira de vacas leiteiras alimentadas com dietas com substituição total de milho por polpa cítrica. O teor dietético do milho foi 10 por cento e o de polpa 24 por cento nos tratamentos com milho, e o de polpa foi 33 por cento nas dietas exclusivas com polpa. A substituição total das fontes inorgânicas Cu, Mn, Se, Zn e Cr por fontes orgânicas foi avaliada simultaneamente. As quatro dietas geradas por arranjo fatorial dos dois fatores foram fornecidas a 16 vacas em Quadrado Latino 4x4. As produções de leite foram 27,5kg para vacas alimentadas com polpa e 28,4kg para aquelas que receberam milho (P=0,04). A substituição total de milho por polpa cítrica reduziu o teor e a produção de proteína no leite (P<0,03), e não afetou a secreção de gordura (P>0,24). Dietas formuladas exclusivamente com polpa cítrica podem ser indicadas quando o pagamento do leite for baseado apenas no volume. A inclusão de milho pode aumentar a renda bruta subtraída do custo alimentar quando a produção de sólidos for valorizada.

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The performance and financial efficiency of dairy cows fed diets formulated by total replacement of corn by citrus pulp was evaluated. Treatments with corn contained 10 percent corn and 24 percent citrus pulp while citrus diets contained 33 percent citrus pulp. The complete replacement of inorganic sources of Cu, Mn, Se, Zn, and Cr by organic sources was simultaneously evaluated. The four diets generated by the factorial arrangement of the two factors were fed to 16 cows in 4x4 Latin Squares. Means of milk production were 27.5kg and 28.4kg for cows fed citrus pulp and corn (P=0.04) diets, respectively. The complete replacement of corn by citrus pulp decreased milk protein production and content (P<0.03) and had no effect on milk fat (P>0.24). Diets formulated exclusively with citrus pulp may be recommended when milk payment is based exclusively on volume, but the inclusion of corn may increase income over feed cost when milk solids are valued.

Asunto(s)

Animales , Femenino , Bovinos , Citrus/efectos adversos , Economía de los Alimentos , Producción de Alimentos , Zea mays/efectos adversos

RESUMEN

Avaliou-se a resposta de vacas leiteiras à substituição total de milho maduro finamente moído por polpa cítrica peletizada. O teor dietético do milho foi 10 por cento e o de polpa 24 por cento nos tratamentos com milho, e o de polpa foi 33 por cento nas dietas exclusivas com polpa. Simultaneamente, foi avaliada a substituição total de fontes inorgânicas de Cu, Mn, Se, Zn e Cr por fontes orgânicas. Quatro dietas baseadas em silagem de milho foram geradas por arranjo fatorial dos dois fatores. Dezesseis vacas receberam os tratamentos em quadrado latino 4x4. O efeito da substituição de fontes inorgânicas por fontes orgânicas de microminerais não foi conclusivo. O consumo diário de matéria seca foi 19,4kg na polpa e 20,5kg na dieta com milho (P=0,03). O consumo de matéria orgânica digestível foi maior nas dietas com milho (P<0,01). Houve tendência de queda na taxa fracional de degradação ruminal in situ da MS da silagem de milho (P=0,11) e de aumento no tamanho da fração indigestível (P=0,15) nas dietas com milho, sugerindo que a degradação de forragens não determinou o menor consumo nas dietas com polpa. A substituição total de milho por polpa cítrica pode reduzir o consumo e a digestibilidade.(AU)

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The response of lactating cows to the total replacement of finely ground mature corn by pelleted citrus pulp was evaluated. Treatments with corn contained 10 percent corn and 24 percent citrus pulp while citrus diets contained 33 percent citrus pulp. The complete replacement of inorganic sources of Cu, Mn, Se, Zn, and Cr by organic sources was simultaneously evaluated. Four corn silage based diets were generated by a factorial arrangement of the two factors. Sixteen cows received the treatments in 4x4 latin squares. The effect of substituting inorganic by organic mineral sources was not conclusive. Daily dry matter intake was 19.4kg for citrus diets and 20.5kg with corn (P=0.03). The digestible organic matter intake was increased by corn supplementation (P<0.01). There was a trend for a decreased fractional rate of in situ ruminal degradation of corn silage dry matter (P=0.11) and for increased size of the indigestible fraction (P=0.15) in diets with corn, suggesting that degradation of forages did not determine the lower intake for citrus diets. The total substitution of corn by citrus pulp may decrease intake and digestibility.(AU)

Asunto(s)

Animales , Femenino , Conducta Alimentaria , Alimentación Animal/efectos adversos , Rumen , Compuestos Orgánicos/efectos adversos , Compuestos Inorgánicos/efectos adversos , Bovinos

RESUMEN

Avaliou-se a resposta de vacas leiteiras à substituição total de milho maduro finamente moído por polpa cítrica peletizada. O teor dietético do milho foi 10 por cento e o de polpa 24 por cento nos tratamentos com milho, e o de polpa foi 33 por cento nas dietas exclusivas com polpa. Simultaneamente, foi avaliada a substituição total de fontes inorgânicas de Cu, Mn, Se, Zn e Cr por fontes orgânicas. Quatro dietas baseadas em silagem de milho foram geradas por arranjo fatorial dos dois fatores. Dezesseis vacas receberam os tratamentos em quadrado latino 4x4. O efeito da substituição de fontes inorgânicas por fontes orgânicas de microminerais não foi conclusivo. O consumo diário de matéria seca foi 19,4kg na polpa e 20,5kg na dieta com milho (P=0,03). O consumo de matéria orgânica digestível foi maior nas dietas com milho (P<0,01). Houve tendência de queda na taxa fracional de degradação ruminal in situ da MS da silagem de milho (P=0,11) e de aumento no tamanho da fração indigestível (P=0,15) nas dietas com milho, sugerindo que a degradação de forragens não determinou o menor consumo nas dietas com polpa. A substituição total de milho por polpa cítrica pode reduzir o consumo e a digestibilidade.

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The response of lactating cows to the total replacement of finely ground mature corn by pelleted citrus pulp was evaluated. Treatments with corn contained 10 percent corn and 24 percent citrus pulp while citrus diets contained 33 percent citrus pulp. The complete replacement of inorganic sources of Cu, Mn, Se, Zn, and Cr by organic sources was simultaneously evaluated. Four corn silage based diets were generated by a factorial arrangement of the two factors. Sixteen cows received the treatments in 4x4 latin squares. The effect of substituting inorganic by organic mineral sources was not conclusive. Daily dry matter intake was 19.4kg for citrus diets and 20.5kg with corn (P=0.03). The digestible organic matter intake was increased by corn supplementation (P<0.01). There was a trend for a decreased fractional rate of in situ ruminal degradation of corn silage dry matter (P=0.11) and for increased size of the indigestible fraction (P=0.15) in diets with corn, suggesting that degradation of forages did not determine the lower intake for citrus diets. The total substitution of corn by citrus pulp may decrease intake and digestibility.

Asunto(s)

Animales , Femenino , Bovinos , Compuestos Inorgánicos/efectos adversos , Compuestos Orgánicos/efectos adversos , Conducta Alimentaria , Rumen , Alimentación Animal/efectos adversos

RESUMEN

Avaliou-se o efeito de ácidos graxos voláteis (AGV) sobre a integridade do epitélio no rúmen, no plano nasolabial, na epicera e no perioplum traseiro e dianteiro de bezerros e validou-se a feitura de biópsias tegumentares como indicadores de alterações morfológicas da mucosa ruminal. Dezessete bezerros, com sonda no rúmen, receberam infusões intra-ruminais de AGV ou salina, durante 37 dias. Aos 89 dias de vida, após o abate, foram colhidas amostras dos tecidos. Os AGV aumentaram a área de epitélio total e a área de células metabolicamente ativas no epitélio ruminal, embora o butirato não tenha induzido ao desenvolvimento papilar. A área de epitélio não queratinizado no plano nasolabial foi reduzida pela infusão de AGV. Butirato e lactato foram mais indutores de alterações patológicas no epitélio ruminal. Não foram observadas lesões histológicas nos epitélios do plano nasolabial, da epicera e do perioplum, mostrando que essas são conseqüências do efeito direto dos AGV sobre o epitélio ruminal. Os efeitos indireto e direto dos AGV sobre a morfologia dos tecidos epiteliais queratinizados não foram iguais. Biópsias tegumentares podem ter utilidade como indicadores de alterações morfológicas da mucosa ruminal.(AU)

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The effect of volatile fatty acids (VFA) on rumen wall, epidermis of nasolabial surface, perioplum, and epicera of calves was evaluated. The experiment also aimed to validate the procedure of tegument biopsies as indicators of ruminal mucosa alterations. Seventeen neonatal calves with foley catheters received intraruminal infusions of VFA or saline, during 37 days. At 89-day-old, the animals were slaughtered and tissue samples were collected from rumen, nasolabial surface, epicera, and perioplum from face and hindquarters. VFA infusion increased total epithelium area and metabolically active ruminal cell area; although butirate did not induce the papilar development. The effect of nasolabial surface VFA infusion was the opposite to that observed in the rumen. No histological lesion was observed on nasolabial surface, epicera, and perioplum, demonstrating that these are consequences of VFA direct effect on ruminal epithelium. Butyrate and lactate induced more alterations on the ruminal epithelium. Indirect and direct VFA effects on keratinized epithelium tissues morphology were not identical. Tegumentary biopsies may be useful as indicators of morphological alterations of ruminal mucosa.(AU)

Asunto(s)

Animales , Anatomía Veterinaria , Ácidos Grasos Volátiles/efectos adversos , Rumen/anatomía & histología , Rumen/ultraestructura , Piel , Bovinos

RESUMEN

Dezessete bezerros foram utilizados para avaliar o efeito de ácidos graxos voláteis (AGV) sobre a morfologia ruminal, a epiderme do plano nasolabial, a epicera e o perioplum, e para validar a execução de biópsias tegumentares como indicadores de alterações da mucosa ruminal. Os animais receberam infusões intra-ruminal de butirato, propionato, lactato ou salina (controle) durante 37 dias. A insulina sorológica foi dosada no 22º dia experimental nos tempos de 0, 90, 180 e 360 minutos em relação à infusão diária da manhã. No 89º dia de vida, após o abate, foram coletados fragmentos ruminais e epidérmicos. Todos os AGV induziram aumento proporcionalmente maior no peso do ruminorretículo que no peso do omaso, sendo o butirato aparentemente mais estimulador da massa do estômago aglandular. Embora o butirato tenha sido mais estimulador da secreção de insulina, os AGV foram incapazes de induzir ganho nas dimensões papilares. Os AGV aumentaram a proliferação celular nos epitélios do rúmen e do perioplum traseiro, contrariamente ao efeito sobre o plano nasolabial e a epicera. Os efeitos dos AGV sobre a morfologia da mucosa ruminal e de outros tecidos queratinizados sugerem que danos morfológicos no rúmen e cascos podem ter causa comum. Biópsias tegumentares podem ter utilidade como indicadores de alterações morfológicas da mucosa ruminal.(AU)

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The effect of butyrate, propionate, and lactate on ruminal wall, epidermis of nasolabial surface, perioplum, and epicera of 17 neonatal calves was evaluated. The experiment also aimed to validate the procedure and interpretation of tegument biopsies as indicators of ruminal mucosa alterations. Serum insulin was sampled on the 22nd day from the beginning of treatments, at 0, 90, 180, and 360 minutes after the morning infusion. After slaughtering, samples were collected from ruminal wall, nasolabial surface, epicera, and perioplum from face and hindquarters. All volatile fatty acids (VFA) induced greater increase in ruminal-reticulum proportionate weight than in omasum. Butyrate was a greater stimulator of non-glandular stomach growth. Although butyrate stimulated more insulin secretion, this VFA was not capable to induced gain on papillae area or height. The effect of nasolabial surface VFA infusion was the opposite to that observed in the rumen. VFA increased hind perioplum mitotic index, contrary to its effect on the nasolabial surface and epicera. VFA effects on ruminal mucosa morphology and on other keratinized tissues suggest that morphological damage on hoof and ruminal epithelium may have a common cause. Tegumentary biopsies may be useful as indicators of morphological alterations of ruminal mucosa.(AU)

Asunto(s)

Animales , Anatomía Veterinaria , Ácidos Grasos Volátiles/efectos adversos , Rumen/anatomía & histología , Piel , Bovinos

RESUMEN

Dezessete bezerros foram utilizados para avaliar o efeito de ácidos graxos voláteis (AGV) sobre a morfologia ruminal, a epiderme do plano nasolabial, a epicera e o perioplum, e para validar a execução de biópsias tegumentares como indicadores de alterações da mucosa ruminal. Os animais receberam infusões intra-ruminal de butirato, propionato, lactato ou salina (controle) durante 37 dias. A insulina sorológica foi dosada no 22º dia experimental nos tempos de 0, 90, 180 e 360 minutos em relação à infusão diária da manhã. No 89º dia de vida, após o abate, foram coletados fragmentos ruminais e epidérmicos. Todos os AGV induziram aumento proporcionalmente maior no peso do ruminorretículo que no peso do omaso, sendo o butirato aparentemente mais estimulador da massa do estômago aglandular. Embora o butirato tenha sido mais estimulador da secreção de insulina, os AGV foram incapazes de induzir ganho nas dimensões papilares. Os AGV aumentaram a proliferação celular nos epitélios do rúmen e do perioplum traseiro, contrariamente ao efeito sobre o plano nasolabial e a epicera. Os efeitos dos AGV sobre a morfologia da mucosa ruminal e de outros tecidos queratinizados sugerem que danos morfológicos no rúmen e cascos podem ter causa comum. Biópsias tegumentares podem ter utilidade como indicadores de alterações morfológicas da mucosa ruminal.

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The effect of butyrate, propionate, and lactate on ruminal wall, epidermis of nasolabial surface, perioplum, and epicera of 17 neonatal calves was evaluated. The experiment also aimed to validate the procedure and interpretation of tegument biopsies as indicators of ruminal mucosa alterations. Serum insulin was sampled on the 22nd day from the beginning of treatments, at 0, 90, 180, and 360 minutes after the morning infusion. After slaughtering, samples were collected from ruminal wall, nasolabial surface, epicera, and perioplum from face and hindquarters. All volatile fatty acids (VFA) induced greater increase in ruminal-reticulum proportionate weight than in omasum. Butyrate was a greater stimulator of non-glandular stomach growth. Although butyrate stimulated more insulin secretion, this VFA was not capable to induced gain on papillae area or height. The effect of nasolabial surface VFA infusion was the opposite to that observed in the rumen. VFA increased hind perioplum mitotic index, contrary to its effect on the nasolabial surface and epicera. VFA effects on ruminal mucosa morphology and on other keratinized tissues suggest that morphological damage on hoof and ruminal epithelium may have a common cause. Tegumentary biopsies may be useful as indicators of morphological alterations of ruminal mucosa.

Asunto(s)

Animales , Anatomía Veterinaria , Ácidos Grasos Volátiles/efectos adversos , Bovinos , Rumen/anatomía & histología , Piel