Efeitos da ingestão subcrônica de arsênio sobre os testículos de camundongos adultos

• Autor(a) principal: Araújo, Jesylaine Oliveira Cunha
• Data de Publicação: 2011
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/2337
• topic: Arsênio; Toxicidade; Contaminante ambiental; Testículo; Célula de Leydig; Estresse oxidativo; Arsenic; Toxicity; Environmental Contaminant; Testis; Cell Leydig; Oxidative Stress; CNPQ::CIENCIAS BIOLOGICAS::BIOLOGIA GERAL

The toxicity of a chemical agent depends on its inherent propensity to produce damage to the biological system with which it interacts. Arsenic (As), a well known environmental pollutant, outstands as potentially toxic element to the male reproductive function. The exposure to As can affect the testicle, resulting in adverse effects on reproduction; several evidences indicate that its toxic action is related to oxidative stress. In order to evaluate the effects of As on the testes of adult mice, the indicators: body biometrics, tubular and intertubular compartments and antioxidant enzymatic activity of catalase (CAT) and superoxide dismutase (SOD) were analyzed after exposure of individuals to different doses of As. Thirty Swiss adult mice at reproductive age were divided in three groups: a control group, which received drinking water, and two others, which received arsenic solution in the concentrations of 0.05 (As1) and 1.0 (As2) mg/L orally. The treatment with both arsenic concentrations did not significantly interfere in most parameters related to the body biometrics and tubular morphometry. There was increase in the mass of kidneys of animals who ingested the highest concentration of As, suggesting possible toxicity in this organ and his increased activity in the process of detoxification; decrease in the proportion of the tunica propria volume and seminiferous epithelium, and increase in the proportion of the lumen in the animals from group As2 were also observed, indicating possible adverse effects on the spermatogenesis, however, significant changes in the tubular diameter and seminiferous epithelium measurements that confirmed these effects were not observed. In the intertubular compartment, both concentrations of As promoted a reduction in the volume and nuclear diameter of Leydig cells and increase in the proportions of lymphatic vessels. However, only the highest concentration (As2) caused decrease of volume of Leydig cell in the intertubular tissue and its relationship nucleoplasmatic. With respect to the enzymatic antioxidant defenses, increased SOD and decrease in the CAT were observed, suggesting a H2O2 production increase concomitantly with the reduction of the antioxidant defense of CAT, causing oxidative stress. The data indicate that subchronic ingestion of As can causes alterations inenzymatic defenses of the testis and affect its endocrine portion without, however, promoting relevant modifications in the tubular compartment histology which would indicate changes in the spermatogenic activity.