Efectos del bosentán sobre la función vascular e inflamación de pacientes diabéticos con enfermedad vascular periférica / Bosentan effects on vascular function and inflammation in diabetic patients with peripheral vascular disease

INTRODUCCIÓN: La endotelina-1 (ET-1) interviene en la regulación del tono vasomotor y remodelado vascular y en la disfunción endotelial. El bloqueante de ET-1, bosentán, podría tener un efecto beneficioso en la enfermedad arterial. OBJETIVO: Analizar la expresión de ET-1, óxido nítrico (NO) e interleucinas 6 y 10 (IL-6, IL-10), en diabéticos con arteriopatía periférica y en controles no diabéticos. Analizar el efecto de bosentán en la expresión de mediadores inflamatorios y en la liberación de NO. PACIENTES: Un total de 3 grupos de sujetos; G1: controles no diabéticos (n = 15), G2: diabéticos con claudicación (n = 15), G3: diabéticos con lesiones tróficas (n = 15). MATERIAL Y MÉTODOS: Análisis de expresión plasmática de ET-1 mediante dot-blot, de concentraciones plasmáticas de IL-6 e IL-10 (kits de ELISA). Capacidad de liberar NO mediante kit de nitratos+nitritos. RESULTADOS: Se observa un aumento de los niveles de ET-1 (G1: 172,9; G2: 277,1; G3: 367,3; p < 0,05, unidades arbitrarias) y un descenso de IL-6 en las formas más avanzadas de la enfermedad (G1: 45,8; G2: 16,4; G3: 9,8; p < 0,05 pg/ml). Bosentán elevó los niveles de IL-6 en el grupo de lesiones tróficas hasta igualarla con el grupo control. Se observó una reducción significativa de la capacidad de liberar NO por los leucocitos en G3 (G1: 16,7; G3: 12; p < 0,05 μmol/L). Este efecto se revirtió significativamente en presencia de bosentán. CONCLUSIONES: Los niveles elevados de ET-1 podrían influir en la progresión de la EAP. En la arteriopatía avanzada parece existir un descenso de la actividad inflamatoria (disminución de IL-6), lo que podría disminuir la vasodilatación (reducción de NO). Bosentán tiene un efecto antagonista sobre estos efectos, fundamentalmente en los estadios más avanzados de la enfermedad

INTRODUCTION: Endothelin-1 (ET-1) is involved in the regulation of vasomotor tone, vascular remodeling, and endothelial dysfunction. The ET-1 blocker, osentan, could have a beneficial effect on vascular disease. OBJECTIVE: To analyze the expression of ET-1, nitric oxide (NO), and interleukins 6 and 10 (IL-6, IL-10), in diabetics with peripheral arterial disease (PAD) and non-diabetic controls. To analyze the effects of bosentan on the expression of inflammatory mediators and the release of NO. PATIENTS: G1: non-diabetic controls (n = 15), G2: diabetic patients with claudication (n = 15), G3: diabetics patients with trophic lesions (n = 15). MATERIAL AND METHODS: Analysis of plasma ET-1 expression by dot-blot, plasma concentrations of IL-6 and IL-10 (ELISA kits). Ability to release NO by nitrate + nitrite kit. RESULTS: Increased levels of ET-1 (G1: 172.9; G2: 277.1; G3: 367.3, P<.05, arbitrary units) and a decrease in IL-6 (G1: 45.8; G2: 16.4; G3: 9.8; P<.05 pg/ml) are observed in the most advanced forms of disease. Bosentan increased levels of IL-6 in the group of trophic lesions when compared with the control group. A significant reduction in the ability of NO release by leukocytes in G3 (G1: 16.7; G3: 12; P<.05 μmol/L) was observed. This effect was significantly reversed in the presence of bosentan. CONCLUSIONS: Elevated levels of ET-1 may influence the progression of PAD. In advanced artery disease, there appears to be a reduction in inflammatory activity (decrease IL-6), which could reduce the vasodilation (NO reduction). Bosentan has an antagonistic effect on these effects, mainly in the more advanced stages of the disease

Metabolic differences between white and brown fat from fasting rabbits at physiological temperature.

It has been suggested that activated brown adipose tissue (BAT) shows increased glucose metabolic activity. However, less is known about metabolic activity of BAT under conditions of fasting and normal temperature. The aim of this study was to compare the possible differences in energetic metabolism between BAT and white adipose tissue (WAT) obtained from rabbits under the conditions of physiological temperature and 24 h after fasting conditions. The study was carried out on New Zealand rabbits (n=10) maintained for a period of 8 weeks at 23±2 °C. Food was removed 24 h before BAT and WAT were obtained. Protein expression levels of the glycolytic-related protein, glyceraldehyde-3-phosphate dehydrogenase, and pyruvate dehydrogenase were higher in WAT than that in BAT. The expression level of carnitine palmitoyltransferase 1 (CPT1) and CPT2, two fatty acid mitochondrial transporters, and the fatty acid ß-oxidation-related enzyme, acyl CoA dehydrogenase, was higher in BAT than in WAT. Cytosolic malate dehydrogenase expression and malate dehydrogenase activity were higher in WAT than in BAT. However, lactate dehydrogenase expression and lactate content were significantly higher in BAT than in WAT. In summary, this study for the first time, to our knowledge, has described how under fasting and normal temperature conditions rabbit BAT seems to use anaerobic metabolism to provide energetic fuel, as opposed to WAT, where the malate-aspartate shuttle and, therefore, the gluconeogenic pathway seem to be potentiated.

Efecto del alprostadil en los cultivos de músculo esquelético isquémico. Estudio proteómico comparativo frente a músculo sano / The effect of alprostadil on ischemic skeletal muscle cultures. Comparative proteomic study with healthy muscle

INTRODUCCIÓN: El alprostadil tiene efecto vasodilatador y antiagregante. Es bien conocido su efecto endotelial, pero se desconocen sus posibles efectos pleiotrópicos sobre el músculo esquelético y si estos difieren en el músculo isquémico. OBJETIVO: Determinar el efecto del alprostadil sobre el metabolismo del músculo esquelético y valorar diferencias en su acción sobre el músculo isquémico frente al sano. MATERIAL Y MÉTODOS: Se obtuvieron muestras de tejido de 10 pacientes con isquemia irreversible intervenidos de amputación supracondílea, tanto de músculo isquémico (extensor corto de los dedos del pie, grupo I) como de músculo sano (músculo cuádriceps del borde de amputación, grupo S). Ambos grupos se cultivaron basalmente y con 5 ng de alprostadil. Se analizó la expresión proteómica de las siguientes enzimas: triosa-fosfato-isomerasa (TPI), malato deshidrogenasa (MDH), lactato deshidrogenasa (LDH) y piruvato carboxilasa (PC). Se determinaron también sus productos, lactato y piruvato. RESULTADOS: La MDH presentó una disminución en el grupo I en las muestras basales (2.196 ± 348 grupo S vs 644 ± 192 grupo I, p < 0,05). La PC estaba aumentada en el grupo I en ambos tipos de muestras (basal: 1,80 ± 1,27 vs 3,16 ± 2,25; alprostadil: 6,72 ± 2,13 vs 8,16 ± 3,63, grupo S vs grupo I, respectivamente, p < 0,05). No hubo diferencias significativas en la concentración de lactato ni en la de piruvato. CONCLUSIONES: La reducción de MDH en el músculo isquémico sugiere una reducción del ciclo de Krebs. El alprostadil estimula la expresión de PC, que induce la formación de oxalacetato; este se introduce en el ciclo de Krebs, permitiéndole funcionar parcialmente en el músculo isquémico y mejorando la obtención de energía

INTRODUCTION: Alprostadil has vasodilator properties and inhibits platelet aggregation. Its effects on endothelial wall have been widely studied, but there is no knowledge about possible skeletal muscle effects, and differences with ischemic muscle. OBJECTIVE: To determine the effects of alprostadil on skeletal muscle metabolism, and to investigate possible differences with ischemic muscle. METHODS: Samples were obtained in 10 patients with leg above-knee amputation due to severe irreversible ischemia, of ischemic muscle (extensor digitorum brevis, group I), and healthy muscle (quadriceps femoris, amputation edge, group S). Muscle segments were incubated with alprostadil 5 ng, or without it (baseline). Proteomic analysis of metabolic enzymes was performed: Triose-phosphate isomerase (TPI), malate dehydrogenase (MDH), lactate dehydrogenase (LDH) and pyruvate carboxylase (PC). Lactate and pyruvate was also determined. RESULTS: A decrease in malate dehydrogenase was observed in group I in the baseline samples (2196 ± 348 group S vs 644 ± 192 group I, P < 0.05). PC was increased in both samples in group I (baseline: 1.80 ± 1.27 vs 3.16 ± 2.25; alprostadil: 6.72 ± 2.13 vs 8.16 ± 3.63, group S vs group I, respectively, P < 0.05). No changes were observed in pyruvate and lactate. DISCUSSION: Decreased MDH in ischemic muscle suggests a Krebs cycle reduction. Alprostadil stimulates the expression of PC, which leads to oxaloacetate production. This product is inserted in Krebs cycle, improving energy obtaining. In this manner, Krebs cycle can work partially in ischemic muscle