Browsing by Subject "Mesterolone"

Now showing 1 - 2 of 2
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    Hepatocyte nuclear phenotype, the cross-talk between anabolic androgenic steroids and exercise in transgenic mice
    (Murcia : F. Hernández, 2008) Fontana, Karina; Aldrovani, Marcela; Paoli, Flávia de; Oliveira, Helena C.F.; Campos Vidal, Benedicto de; da Cruz Hoflingl, M.A.
    The growing and indiscriminate use of high doses of anabolic androgenic steroid (AAS) among youth and athletes has raised serious concerns about its hepatotoxic effects. Herein, the influence of AAS in the nuclear phenotype of hepatocytes was investigated in sedentary and trained mice heterozygous for the human CETP (cholesteryl ester transfer protein) transgene and for LDL-receptor null allele (CETP+/-LDLr+/-) by image analysis. Five groups were assayed comprising treadmill exercised (Ex) and sedentary (Sed) mice, administered mesterolone (AAS) or gum arabic (GA) and a sedentary blank control: G1(SedAAS), G2(SedGA), G3(ExAAS), G4(ExGA), and G5(SedBL). To assess nuclear phenotypes, the state of chromatin supraorganization, DNA content and fragmentation (TUNEL assay), area and perimeter of hepatocytes were determined in Feulgen-stained liver imprints. In addition, the activity of aspartate aminotransferase (AST) and alanine aminotransferase (ALT) hepatic transaminases were measured. SedAAS-G1 showed the lowest chromatin condensation and highest Feulgen-DNA content, polyploid nuclei frequency, nuclear area and perimeter, suggesting gene activation. Contrarily, ExAAS-G3 showed a highest chromatin condensation, and a significant decrease of Feulgen-DNA content and decreased frequency of polyploid nuclei, which suggest gene silencing. Image analysis of the nuclear phenotype offered a coherent descriptive picture of the changing patterns of chromatin organization, which were shown to be congruent with the levels of Feulgen-DNA content, geometric nuclear parameters and hepatocyte activity. In this study, the image analysis permitted the monitoring of the nuclear response to mesterolone and physical exercise action in liver cells, the molecular mechanism of which is in prospect.
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    Regulation of neuronal and endothelial nitric oxide synthase by anabolic-androgenic steroid in skeletal muscles
    (F. Hernández y Juan F. Madrid. Universidad de Murcia. Departamento de Biología Celular e Histología, 2012) Fontana, Karina; Rocha, Thalita; da Cruz-Höfling, Maria Alice
    Anabolic-androgenic steroids (AAS) and exercise share comparable effects on myogenic differentiation, force development, fiber growth and skeletal muscle plasticity. The participation of nitric oxide synthase (NOS) on these effects was only demonstrated in response to exercise. Using immunohistochemistry and western blotting we examined the effect of AAS on the expression of NOS I and III isoforms in three muscles, distinct metabolically and physiologically: soleus (SOL), tibialis anterioris (TA) and gastrocnemius (GAS). Mice with a lipid profile akin to humans were used. Sedentary mice (Sed-C) or exercised, submitted to six-weeks of aerobic treadmill running (one hour/day, 5 days/week) were administered mesterolone (Sed-M and Ex-M, respectively) or gum arabic (vehicle, Ex-C) during the last three weeks, three alternate days per week. Consistently, The TA showed the strongest labeling and the SOL the weakest with NOS III predominating over NOS I. Mesterolone administered to sedentary mice (Sed-C x Sed-M) significantly upregulated NOS I in TA and SOL and NOS III in all three muscles. Mesterolone administered to exercised mice (Ex-C x Ex-M) upregulated NOS I in all three muscles and NOS III in TA and SOL. The exercise to mesterolone-treated mice (Sed-M x Ex-M) produced a strong increase in NOS I expression in GAS; in contrast it antagonized the mesterolone-induced upregulation of NOS I in TA muscle and NOS III in SOL and GAS. The data show nitric oxide (NO) as a potential signaling mediator of AAS effects in skeletal muscle and that NOS I and NOS III upregulations were muscle phenotype-specific. These may be regarded as an indication of the complex NOS/NO signaling mechanism related with AAS effects vs. metabolic/physiological muscle characteristics.