Clastogenic and cytotoxic effects of lipid peroxidation products generated in culinary oils submitted to thermal stress.

In rats, the administration of oil submitted to high temperatures is teratogenic. To understand the mechanisms involved, the clastogenic and cytotoxic effects were studied respectively in lymphocytes, hepatocytes (HepG2) and in human umbilical vein endothelial cells (HUVEC) cultured with a water extract obtained from heated oil (HO). In lymphocytes incubated with HO containing 0.075 or 0.15 microM of thiobarbituric reacting substances, the rate of chromosomal breakage was 18.4% and 23.1%, compared to 8.7% and 6.6%, or 8.1% and 9.2%, respectively in lymphocytes incubated with the same volume of a water extract from non-heated oil (NHO) or distilled water (DW). In HepG2 or HUVEC cells, the cytotoxic properties of the HO were dose dependent, the cytotoxicity beginning at concentrations as low as 0.25 microM. In contrast, the same volume of NHO or DW was non-toxic for these cells. The results obtained show that a water extract obtained from heated oil is clastogenic and, in higher doses, cytotoxic.

Inducción de hiperglucemias moderadas en ratas wistar por inoculación neonatal de estreptozotocina: ¿Inyección subcutánea o intraperitoneal? / Moderate Hyperglycemia Induction in Wistar Rats by Neonatal Streptozotocin Inoculation: Subcutaneous or Intraperitoneal Injection?

La experimentación en modelos animales es una herramienta importante para comprender los mecanismos fisiopatológicos que caracterizan la diabetes mellitus. Dado que es necesario conocer la implicación de cada variante seleccionada en la concepción del modelo de diabetes a utilizar, en este caso de hiperglucemias moderadas, proponemos evaluar en ratas adultas el efecto de la administración neonatal (subcutánea o intraperitoneal) de estreptozotocina (STZ) sobre su estado metabólico y oxidativo. Se indujo diabetes en gazapos hembras de dos días de nacidos mediante la inoculación de 100 mg/Kg de peso corporal de STZ. Los grupos, de 10 animales cada uno, se definieron según la vía de inoculación subcutánea (SC) o intraperitoneal (IP). Los neonatos designados como controles recibieron (SC o IP) únicamente vehículo. El fenotipo se manifestó a las 6 semanas de vida en ambos grupos. El grupe STZ SC mostró un promedio semanal de glucemias significativamente mayor y un peor control glucémico durante el experimento, reflejado por los valores de hemoglobina glicosilada. A las 12 semanas se realizó la eutanasia y se estudiaron indicadores del perfil renal, lipídico y estrés oxidativo. En los grupos tratados con STZ, respecto a los tratados solamente con vehículo, no existen diferencias significativas en el lipidograma y uricemia; únicamente la creatininemia y la uremia son significativamente mayores en STZ SC vs. CONTROL SC y STZ IP. El análisis estadístico de los parámetros del estado oxidativo [malonildialdehído (MDA) y productos avanzados de la oxidación a proteínas (PAOP)] no muestra diferencias entre los grupos estudiados. Se concluye que, si bien por ambas vías de inducción se logra instaurar el modelo deseado, desde el punto de vista metabólico los animales en los que se utilizó la vía SC el fenotipo se manifiesta con mayor similitud a lo que ocurre en el síndrome diabético humano, fundamentalmente en lo referido a los parámetros de la función renal. Rev Argent Endocrinol Metab 51:178-184, 2014 Los autores declaran no poseer conflictos de interés.

Animal experimentation is an important tool for understanding the pathophysiological mechanisms characterizing diabetes mellitus type 2 (DMT2). Based on the fact that it is necessary to know the implication of each variant selected in DMT2 models, in this case of moderate hyperglycemias, we propose to evaluate the metabolic and oxidative stress status in adult rats after neonatal [subcutaneous (SC) or intraperitoneal (IP)] administration of streptozotocin (STZ). Thus, DMT2 was induced by either SC or IP injection of 100 mg/Kgbody weight of streptozotocin (STZ) in 2 day-old rat female offsprings. Neonates designated as controls received only vehicle in a similar schedule. Groups of 10 animals were defined by the route of injection (SC or IP). Hyperglycemia developed at 6 weeks of life in both experimental groups; however, rats from the group receiving STZ SC displayed a significantly higher weekly average of blood glucose levels and a poorer glycemic control during the experiment (indicated by the peripheral glycosylated hemoglobin levels). At 12 weeks of age, euthanasia was performed, and indicators of kidney function, peripheral lipid profile and oxidative stress parameters were studied. In STZ-treated rats, there were no significant differences in circulating concentrations of lipids, uric acid, MDA and PAOP, compared with controls. Interestingly, peripheral creatinine and urea concentrations were significantly higher in STZ SC-treated rats than in both CONTROL SC and STZ IP rats. We conclude that, although the DMT2 phenotype could be obtained by neonatal STZ administration by either route, the phenotype developed by animals inoculated with STZ by the SC route was more similar to that occurring in the human diabetic syndrome, mainly as regards renal function parameters. Rev Argent Endocrinol Metab 51:178-184, 2014 No financial conflicts of interest exist.