title: Microcystin extracts induce ultrastructural damage and biochemical disturbance in male rabbit testis.
abstract: In the present research, the changes of ultrastructures and biochemical index in rabbit testis were examined after i.p. injection with 12.5 microg/kg microcystin (MC) extracts. Ultrastructural observation showed widened intercellular junction, distention of mitochondria, endoplasmic reticulum, and Golgi apparatus. All these changes appeared at 1, 3, and 12 h, but recovered finally. In biochemical analyses, the levels of lipid peroxidation (MDA) and H(2)O(2) increased significantly at 1 h, indicating MC-caused oxidative stress. Finally, H(2)O(2) decreased to the normal levels, while MDA remained at high levels. The antioxidative enzymes (CAT, SOD, GPx, GST) and antioxidants (GSH) also increased rapidly at 1 h, demonstrating a quick response of the defense systems to the oxidative stress. Finally, the activity of CAT, SOD, and GPX recovered to the normal level, while the activity of GST and the concentration of GSH remained at a high level. This suggests that the importance of MCs detoxification by GST via GSH, and the testis of rabbit contained abundant GSH. The final recovery of ultrastructure and some biochemical indexes indicates that the defense systems finally succeeded in protecting the testis against oxidative damage. In conclusion, these results indicate that the MCs are toxic to the male rabbit reproductive system and the mechanism underlying this toxicity might to be the oxidative stress caused by MCs. Although the negative effects of MCs can be overcome by the antioxidant system of testis in this study, the potential reproductive risks of MCs should not be neglected because of their wide occurrence.
authors.affiliation: Donghu Experimental Station of Lake Ecosystems, State Key Laboratory of Freshwater Ecology and Biotechnology of China, Institute of Hydrobiology, The Chinese Academy of Sciences, People's Republic of China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Liu
authors.forename: Ping
authors.initials: P
authors.lastname: Xie
authors.forename: Tong
authors.initials: T
authors.lastname: Qiu
authors.forename: Hui-Ying
authors.initials: HY
authors.lastname: Li
authors.forename: Guang-Yu
authors.initials: GY
authors.lastname: Li
authors.forename: Le
authors.initials: L
authors.lastname: Hao
authors.forename: Qian
authors.initials: Q
authors.lastname: Xiong
mesh_terms: D000818:Animals; D006861:Hydrogen Peroxide; D008297:Male; D008315:Malondialdehyde / Q000378:metabolism; D052998:Microcystins / Q000737:chemistry / Q000633:toxicity*; D015394:Molecular Structure; D018384:Oxidative Stress; D011817:Rabbits; D012708:Sertoli Cells / Q000187:drug effects / Q000648:ultrastructure; D013737:Testis / Q000187:drug effects* / Q000378:metabolism / Q000648:ultrastructure*
chemical_list: D052998:Microcystins; D008315:Malondialdehyde; D006861:Hydrogen Peroxide