Testicular morphology and morphometry in mice chronically exposed to arsenic / Morfologia e morfometria testicular de camundongos adultos submetidos à exposição crônica ao arsenato

AUTOR(ES)
DATA DE PUBLICAÇÃO

2009

RESUMO

There is an increasing concern about the potentially harmful effects of several environmental pollutants, as for instance, the inorganic arsenic, one of the main pollutants of the water worldwide. The intoxication by arsenic can be acute or chronic, and lead to a variety of pathologies and impairment of male reproductive system. This work aimed to investigate the chronic effects of the arsenic exposure on biometric and testicular parameters of adult mice. Tissue accumulation of arsenic was verified in reproductive organs, skin, liver and kidneys. Twenty-four mice were divided in three groups, which received treatment in the drinking water: 1) control, which received distilled water, 2) arsenic 1 (AS1), which received a solution of sodium arsenate at the concentration of 1.0 mg L-1, during 42 days; and 3) arsenic 2 (AS2), which received a solution of sodium arsenate at the concentration of 1.0 mg L-1, during 84 days. After sacrifice, sexual organs, liver, kidneys and skin were collected and immersed in Karnovsky fixative solution. The testes were processed and dyed in toluidina/borate of sodium blue for the histopathological analyses. The treatment with sodium arsenate at the concentration of 1.0 mg L-1 increased body weight in the AS2 group, compared to AS1 and control. However, the testicular weight did not vary significantly among the treated groups. Accessory sexual organs as epididim, seminal vesicle and deferential duct did not present changes in weight. The prostate had its weight reduced in the two treatment groups. The same happened for the kidneys and liver. There was arsenic accumulation in all of the analyzed organs and it was larger in the animals that were exposed to the poison longer. Alanina aminotransfrase did not present alterations. Aspartato aminotranferase (AST) increased in the group of animals that received arsenic longer. The increase of ALT signals the toxicity of arsenic in the hepatic and renal functions, motivating, thus future histological and morphometric studies on these organs. The proportion of the tunica propria was increased in the groups treated compared to the control, suggesting a possible protective action of the arsenate in the seminiferous tubules, once the tunica propria is part of the hemato-testicular barrier that promotes protection of the cells of espermatogenic lineage inside the seminiferous tubules. However the proportion of the seminiferous epithelium was reduced significantly in the 42-day treatment group. The tubular diameter and the seminiferous epithelium were shown to be recovered in the 84- day treatment group compared to the 42- day group. Arsenic caused different testicular pathologies, particularly in the seminiferous tubules. There was a reduction in the proportion of cells of Leydig, as well as in their nuclear diameter and volume. Besides, there was a significantly increased number of macrophages in the animals exposed to the action of arsenic for a longer time. The blood vessel was significantly reduced in As2 in relation to As1 and control, unlike what happened in relation to As1, where there was an increase in this proportion. For the lymphatic vessel, the increase in the treated groups was significant. The volume of cells of Leydig and conjunctive tissue were reduced in the treated groups. For the macrophages volume, a significant increase was observed in As2 in relation to As1 and control. In relation to the blood vessel, the volume of As1 increased significantly in relation to the control, decreasing significantly in As2. In relation to the two treated groups, the blood vessel volume reduced in As2. However, for the volume of lymphatic vessel, a significant increase was observed in the groups treated in relation to the control group. In the morfometry of the cells of Leydig, nuclear diameter, the nucleus proportion and cytoplasm, ILS and nuclear volume were reduced significantly in the two treatment groups. However, the nucleoplasmatic relationship (NPR) was reduced significantly just in the 42-day group. This way we detected that arsenic affects the endocrine portion of the testicle. The plasmatic levels of testosterone were shown to be reduced in the two treatment groups. This work confirmed the toxicity of arsenic in the concentration of 1mg/l in two different exposure times. The data presented allow us to suggest that the treatments, in this arsenic concentration, did not interfere with the tubular morphometry. However, it caused alterations in the testicular and body biometry, besides the confirmation of its cumulative nature in several organs and strong indicators of its toxicity in the hepatic and renal functions of mice in reproductive age. The germinative epithelium in the two treatment groups was disorganized, which certainly damaged the spermatogenic process. Sodium arsenate alters the morphometric parameters of the cells of Leydig besides leading to a reduction in the levels of plasmatic testosterone confirming the toxicity of this element in the masculine reproductive system.

ASSUNTO(S)

camundongos histopatologia testosterona arsênio seminiferous tubule túbulo seminífero testosterone biologia geral arsenic histopathology mice

ACESSO AO ARTIGO

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