Abstract：
Potential endocrine-disrupting properties of cyanotoxins, such as microcystin-LR (MC-LR) and cylindrospermopsin (CYN) are of concern due to their increasing occurrence, the scarcity of reports on the topic (particularly for CYN) and the impact of human\'s health at different levels. Thus, this work performed for the first time the uterotrophic bioassay in rats, following the Organization for Economic Cooperation and Development (OECD) Test Guideline 440, to explore the oestrogenic properties of CYN and MC-LR (75, 150, 300 μg/kg b.w./day) in ovariectomized (OVX) rats. Results revealed neither changes in the wet and blotted uterus weights nor in the morphometric study of uteri. Moreover, among the steroid hormones analysed in serum, the most remarkable effect was the dose-dependent increase in progesterone (P) levels in rats exposed to MC-LR. Additionally, a histopathology study of thyroids and serum levels of thyroids hormones were determined. Tissue affectation (follicular hypertrophy, exfoliated epithelium, hyperplasia) was observed, as well as increased T3 and T4 levels in rats exposed to both toxins. Taken together, these results point out that CYN and MC-LR are not oestrogenic compounds at the conditions tested in the uterotrophic assay in OVX rats, but, however, thyroid disruption effects cannot be discarded.
摘要：
氰基毒素的潜在内分泌干扰特性，例如微囊藻毒素-LR（MC-LR）和圆柱精氨素（CYN）由于其发病率增加而受到关注，关于该主题的报告（特别是对于CYN）的稀缺性以及不同级别的人类健康影响。因此，这项工作首次在大鼠中进行了子宫营养生物测定，根据经济合作与发展组织（OECD）测试指南440，探讨去卵巢（OVX）大鼠中CYN和MC-LR（75、150、300μg/kg体重/天）的雌激素特性。结果显示，子宫的湿重和印迹重量以及子宫的形态计量学研究均未发生变化。此外，在血清中分析的类固醇激素中，最显着的效果是暴露于MC-LR的大鼠中孕酮（P）水平的剂量依赖性增加。此外,对甲状腺的组织病理学研究和血清甲状腺激素水平进行了测定。组织矫治（卵泡肥大，上皮脱落，增生)被观察到，以及暴露于两种毒素的大鼠的T3和T4水平升高。一起来看,这些结果表明，CYN和MC-LR在OVX大鼠的子宫营养测定中测试的条件下不是雌激素化合物，但是,然而,甲状腺破坏效应不能被丢弃。
