Sufrimiento fetal, lipoproteinas y lipoperoxidación / Feat distress, lipoproteins and lipid peroxidation

Introducción: Los niveles de lípidos y lipoproteínas del recién nacido (RN) están altamente influidos por factores materno-fetales y perinatales. Entre ellos, destacan la edad gestational, el peso al nacer y ciertos problemas materno-fetales relacionados con el sufrimiento fetal (SF). Objetivo: Determinar si la presencia de SF durante el parto puede modificar el perfil lipoproteico y los niveles de peroxidación lipídica del RN. Material y métodos: Mediante un estudio caso-control se estudian las modificaciones en el perfil lipídico (colesterol total, triglicéridos, colesterol-HDL [cHDL], colesterol-LDL [cLDL], VLDL, apoproteínas [Apo-A 1 y B]) y grado de peroxidación (TBARS) en sangre de cordón de 71 RN con SF, y se comparan con 1.067 neonatos controles. Se calculó la sensibilidad, especificidad y área bajo la curva ROC de la hipertrigliceridemia neonatal. Resultados: Los RN con SF tienen un aumento muy significativo de los triglicéridos plasmáticos (55,3 mg/dL frente a 36,9 mg/dL; P 90 mg/dL; P 97,5) en RN con SF fue del 11,3 por ciento, notablemente superior al 1,7 por ciento descrito en el grupo control (OR= 7,40; P <0,0001), con igual comportamiento por etnias. Como indicativa de SF, la hipertrigliceridemia fetal presenta una alta especificidad (98,3 por ciento), pero una baja sensibilidad (S= 11,3 por ciento). El área bajo la curva ROC no presentó un nivel de eficiencia adecuado. Conclusiones: La existencia de SF es uno de los principales factores que modifica cua-litativa y cuantitativamente el perfil lipídico del RN, incrementando notablemente los tri-glicéridos plasmáticos y VLDL, y disminuyendo ligeramente el cHDL en sangre de cordón, con independencia del grupo étnico. De todas las alteraciones, la más importante la experimentan los triglicéridos, por lo que puede ser utilizado como parámetro indicativo de SF. El SF no parece incrementar la generación de radicales libres y los fenómenos de peroxidación lipídica en el momento del parto. La trigliceridemia en sangre de cordón es un parámetro complementario de utilidad en la sospecha de sufrimiento fetal. Su escasa sensibilidad diagnóstica desaconseja su determinación sistemática como parámetro discriminante básico del SF (AU)

Myocardial and skeletal muscle aging and changes in oxidative stress in relationship to rigorous exercise training.

Cardiac and skeletal muscle are very different functional tissues, and we would expect a variation in the ROS generation, in ageing and rigorous exercise-related in both tissues. We determined TBARS, total SOD, Cu, ZnSOD and MnSOD activities, and the patterns of SOD isoenzymes in skeletal muscle and heart of male Wistar rats, young and old, in rest and after rigorous exercise. There were no differences in the levels of lipoperoxidation in aged rest animals in both tissues, but the level was increased after exhaustion. The level of SOD activities was bigger in the heart than in skeletal muscle. Total SOD and Cu, ZnSOD activities were higher in old rest animals in the skeletal muscle than in young rest rats. This change did not occur in the heart. After rigorous exercise, the level of SOD activities was increased in young rats in both tissues. However, in old exhausted rats, the activities were only elevated in the heart. Different Cu, ZnSOD isoenzyme patterns showed in relation to tissues. In the skeletal muscle in old animals, the Cu, ZnSOD isoenzyme pattern was modified. The rigorous exercise did not change this pattern. The pattern of MnSOD isoenzyme was not varied in either tissue, age nor and exercise.

Age and exercise-related changes in lipid peroxidation and superoxide dismutase activity in liver and soleus muscle tissues of rats.

Thiobarbituric acid-reactive substances (TBARS) level, as marker of lipid peroxidation, and superoxide dismutase (SOD) activity, as endogenous antioxidant enzyme, were examined in liver and soleus muscle tissue of young and old male Wistar rats. We established different types of exercise running on a treadmill both for young and old rats, investigated the effect of aging, exhaustion and training on these groups. The hepatic TBARS levels were raised in the short-training young group and in the long-training old group. On the other hand, the TBARS content decreased in soleus muscle in the short-training young group, and long-training exercise enhanced lipid peroxidation in old rats. SOD activity increased in liver in short-training group. while this activity showed the lowest values in long-training old rats. With respect to soleus muscle tissue, SOD activity was elevated after exhaustive exercise in young rats and old rats had the highest activity in the long-training old group. These findings suggest that free radicals play a role in aging and that the different type, intensity and duration of exercise modify the lipid peroxidation level and antioxidant enzyme activity.