| ObjectTo Construct the experimental n-hexane inhalation model of SD rat, and to discuss the stability, repeatability of the model and its improved application. To observe the pathological changes in ovary or testis of the SD rats after n-hexane inhalation, and to discuss the toxicity mechanism of n-hexane, in order to provide reference for the research of epidemiology and toxicologyMethods48 adult healthy rats were randomly divided into four groups: one control group and three n-hexane groups (1d, 3d and 7d), 6 cases for each group. The rats were placed in a special box, 8 hours per day. Primary concentration of n-hexane was 35.2g/m~3 within the box. After n-hexane inhalation, SD rats were killed within 30min, and n-hexane concentration of blood which extracted from celiac artery was detected. The data of SOD(superoxide dismutase), GSH-Px(glutathione peroxidase), MDA(malondialdehyde) and GSH(Glutathione) were measured by photometry. Organ Coefficients of ovary and testis were calculated. The ovary and testis were embedded with paraffin and HE staining in the routine for observation under microscope. The expressions of F1s, FasL, bax and bcl-2 protein were examined by immunohistochemistry.ResultsThe average concentration of n-hexane in blood of three n-hexane groups respectively were 636.92ug/L,913.49ug/L and 1090.69ug/L, and were clearly higher than normal. It was showed that the SD rat model was successful. The pathological changes of ovary or testis were decided and apparent.As the time of n-Hexane effect increased, the damages in testis or ovary were gradually fearful. In the testis, at seminiferous tubule, the conformation of sustentacular cells (Sertoli cell ) was unclear, spermatogenic cells arranged loose and mussily. In some seminiferous tubules, few "multinucleated giant cells" could be seen, spermatogenic cells badly felled off. In ovary, amount of growth follicles decreased, and oocytes became abnormal at its nuclear membrane and nucleolus. The zona pellucida, which surrounded oocyte was misty and even melted. Both the weight and organ coefficients of injured testis or ovary reduced and were statistically significant (p＜0.05). As the time ofn-hexane effect increased, the activities of SOD, GSH-Px and GSH were decreased, but the content of MDA was increased, especial in the 7d group (p＜0.01).Positive reactions of Fas, FasL and bax were showed in 7d group of injured testis, and located in spermatogenic cells. The expressions were more intensity than these in normal testis. But for injured ovary, semblable reactions were located in granulosa cells and corpus luteum.Conclusion1. It was showed that n-hexane inhalation induced damages in SD rats. This model was simple, reliable and repeatable. It could provide reference for epidemiology and toxicology research ofn-hexane inhalation.2. The pathological changes of ovary or testis were decided and apparent, the weight and organ coefficient of ovary or testis were lower than normal. It was confirmed that n-hexane inhalation induced damages in ovary or testis of SD rats. The more n-hexane inhalation time, the more serious damages for ovary and testis3. According to the data of SOD, GSH-Px, MDA and GSH of injured ovary and testis, it was showed that there was a lot of products from lipid peroxidation, and that lipid-preoxidation might be the mostly damaging process for ovary or testis.4. The expressions of Fas, FasL, bax and bcl-2 protein related with cell apoptosis. In the injured SD rats, the expressions were actively but different characteristics between ovary and testis. It was showed that n-hexane inhalation quickened cell apoptosis. Although apoptosis process of the germ cells were individually in injured ovary and testis, yet n-hexane inhalation disturbed apoptosis to influence the functions of ovary or testis. |
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