Abstract：
Exposure to the neonicotinoid insecticide, imidacloprid (IMI), causes reproductive toxicity in mammals and reptiles. However, reports on the effects of IMI on the gonads in birds are grossly lacking. Therefore, this study investigated the effects of pubertal exposure to IMI on the histology, ultrastructure, as well as the cytoskeletal proteins, desmin, smooth muscle actin and vimentin, of the gonads of Japanese quail (Coturnix coturnix japonica). Quails were randomly divided into four groups at 5 weeks of age. The control group was given only distilled water, whereas, the other three experimental groups, IMI was administered by oral gavage at 1.55, 3.1, and 6.2 mg/kg, twice per week for 4 weeks. Exposure to IMI doses of 3.1 and 6.2 mg/kg caused dose-dependent histopathological changes in the ovary and testis. In the ovary, accumulation of lymphocytes, degenerative changes, and necrosis with granulocyte infiltrations were observed, while in the testis, distorted seminiferous tubules, germ cell sloughing, vacuolisations, apoptotic bodies, autophagosomes, and mitochondrial damage were detected. These changes were accompanied by a decreased number of primary follicles (P ≤ 0.05) in the ovary and a decrease (P ≤ 0.05) in the epithelial height, luminal, and tubular diameters of seminiferous tubules at the two higher dosages. In addition, IMI had a negative effect on the immunostaining intensity of desmin, smooth muscle actin, and vimentin in the ovarian and testicular tissue. In conclusion, exposure to IMI during puberty can lead to a range of histopathological alterations in the gonads of Japanese quails, which may ultimately result in infertility.
摘要：
暴露于新烟碱杀虫剂，吡虫啉(IMI),导致哺乳动物和爬行动物的生殖毒性。然而,关于IMI对鸟类性腺的影响的报道非常缺乏。因此,这项研究调查了青春期暴露于IMI对组织学的影响，超微结构，以及细胞骨架蛋白，desmin,平滑肌肌动蛋白和波形蛋白，日本鹌鹑（Coturnixcoturnixjaponica）的性腺。在5周龄时将鹌鹑随机分为四组。对照组只给予蒸馏水,然而,其他三个实验组，IMI的剂量为1.55、3.1和6.2mg/kg，每周两次，共4周。暴露于3.1和6.2mg/kg的IMI剂量会导致卵巢和睾丸的剂量依赖性组织病理学变化。在卵巢里,淋巴细胞的积累，退行性变化，并观察到有粒细胞浸润的坏死，在睾丸里,扭曲的生精小管，生殖细胞脱落，空泡化,凋亡体，自噬体，并检测到线粒体损伤。这些变化伴随着卵巢中初级卵泡数量的减少（P≤0.05）和上皮高度的减少（P≤0.05），管腔,和两个较高剂量的生精小管的管状直径。此外,IMI对结蛋白的免疫染色强度有负面影响，平滑肌肌动蛋白，卵巢和睾丸组织中的波形蛋白。总之,在青春期暴露于IMI会导致日本鹌鹑性腺的一系列组织病理学改变，这最终可能会导致不孕。
