ABSTRACT
Congenital hypothyroidism was induced in rats by adding 0.05% 6-propyl-2-thiouracil in the drinking water from day 9 of gestation, and continually up to postnatal day 15. Structural alterations observed by light microscopy of seminiferous tubules and by transmission electron microscopy of Sertoli cells of treated animals were consistent with hypothyroid condition. Hypothyroidism was also associated with high phospho-p38 mitogen-activated protein kinase and decreased phospho-extracellular signal-regulated kinase 1/2 levels. Furthermore, the phosphorylation and the immunoreactivity of cytoskeletal-associated vimentin were increased without altering vimentin expression, suggesting an accumulation of insoluble and phosphorylated vimentin. These alterations in intermediate filament dynamics could result in loss of Sertoli cell cytoskeletal integrity and be somewhat related to the deleterious effects of hypothyroidism in testis. In addition, the mitochondrial alterations observed could also be related to defective cytoskeletal dynamics implying in cell damage. Moreover, we observed decreased oxygen consumption and unaltered lipid peroxidation in hypothyroid testis. However, we demonstrated decreased enzymatic and non-enzymatic antioxidant defenses, supporting an increased mitochondrial reactive oxygen species (ROS) generation, contributing to biochemical changes in hypothyroid testis. In addition, the changes in the testis histoarchitecture could be ascribed to cytoskeletal alterations, decreased antioxidant defenses, and increased ROS generation, leading to oxidative stress in the organ.
Subject(s)
Antioxidants/metabolism , Congenital Hypothyroidism/metabolism , Propylthiouracil , Testis/metabolism , Vimentin/metabolism , Animals , Congenital Hypothyroidism/chemically induced , Congenital Hypothyroidism/pathology , Cytoskeleton/metabolism , Lipid Peroxidation , Male , Mitochondria/metabolism , Oxygen Consumption , Phosphorylation , Rats , Rats, Wistar , Reactive Oxygen Species/metabolism , Seminiferous Tubules/metabolism , Seminiferous Tubules/pathology , Sertoli Cells/metabolism , Sertoli Cells/pathology , Testis/pathology , p38 Mitogen-Activated Protein Kinases/metabolismABSTRACT
Hyperthyroidism was induced in rats and somatic indices and metabolic parameters were analyzed in testis. In addition, the morphological analysis evidenced testes maturation and intense protein synthesis and processing, supporting the enhancement in vimentin synthesis in hyperthyroid testis. Furthermore, vimentin phosphorylation was increased, indicating an accumulation of phosphorylated vimentin associated to the cytoskeleton, which could be a consequence of the extracellular-regulated kinase (ERK) activation regulating the cytoskeleton. Biomarkers of oxidative stress demonstrated an increased basal metabolic rate measured by tissue oxygen consumption, as well as, increased TBARS levels. In addition, the enzymatic and non-enzymatic antioxidant defences appeared to respond according to the augmented oxygen consumption. We observed decreased total glutathione levels, with enhancement of reduced glutathione, whereas most of the antioxidant enzyme activities were induced. Otherwise, superoxide dismutase activity was inhibited. These results support the idea that an increase in mitochondrial ROS generation, underlying cellular oxidative damage, is a side effect of hyperthyroid-induced biochemical changes by which rat testis increase their metabolic capacity.
Subject(s)
Hyperthyroidism/pathology , Oxidative Stress , Testis/growth & development , Vimentin/metabolism , Animals , Body Weight , Enzymes , Extracellular Signal-Regulated MAP Kinases/metabolism , Gene Expression Regulation , Glutathione/metabolism , Glycoprotein Hormones, alpha Subunit/blood , Hyperthyroidism/chemically induced , Lipid Peroxidation , Male , Organ Size , Oxygen Consumption , Phosphorylation , RNA, Messenger/genetics , RNA, Messenger/metabolism , Rats , Rats, Wistar , Testis/cytology , Testis/ultrastructure , Thyroid Hormones/blood , Vimentin/geneticsABSTRACT
BACKGROUND AND AIMS: Evaluate the influence of tomato powder in diets differing in energy level on antioxidant status in blood and liver of rats. METHODS: Twenty-four adult male Wistar rats weighing 150-180 g were placed four groups (n=6). For 28 days, animals were fed a diet that was either hyper energetic or hypo energetic. Some diets were supplemented with tomato powder. Liver and blood were collected for analysis of antioxidant enzymes, non-enzymatic antioxidants, thiobarbituric acid reactive species, ubiquinol 9, alpha-tocopherol, lycopene and beta-carotene. Data were analysed by two-way ANOVA. RESULTS: Food intake and thiobarbituric acid-reactive substances contents in liver and plasma were significantly decreased by tomato powder at both energy levels. After tomato powder supplementation, the hepatic levels of ubiquinol 9, alpha-tocopherol, lycopene and beta-carotene were significantly enhanced. In plasma, only the contents of lycopene and beta-carotene were enhanced. The erythrocytic and hepatic activities of catalase were lower, while those of glutathione peroxidase were higher after the ingestion of tomato powder. Total and reduced glutathione contents in liver showed lower levels in cafeteria-fed rats compared to the hypo energetic diet. CONCLUSIONS: The data suggest that the lycopene and beta-carotene component in the tomato power supplement might be beneficial for the prevention of oxidative damage in rats fed both types of energetic diets.
