Toxic effects of microcystin-LR on the reproductive system of male Rana nigromaculata in vitro.
This study aims to demonstrate that microcystin-LR (MC-LR) has toxic effects on the reproductive system of male Rana nigromaculata in vitro. R. nigromaculata were treated with 0, 0.1, 1, 10, and 100 nmol/L of MC-LR for 6 h. Results show that exposure to 1 nmol/L to 100 nmol/L of MC-LR decreased sperm motility and number of sperm cells and increased the sperm abnormality rate, whose values were significantly different from those of the control (P<0.01). Moreover, the same dosage of MC-LR increased reactive oxygen species production and malondialdehyde content. At the same time, antioxidant enzyme (catalase and glutathione S-transferase) activity and glutathione reduced content rapidly increased, whereas antioxidant enzyme superoxide dismutase activity significantly decreased. These results imply that the defense system of the testes quickly responds to oxidative stress. Ultrastructural observation shows distention of the mitochondria, endoplasmic reticulum, and Golgi apparatus and changes in the mitochondrial matrix color, cristae number, and morphology. Moreover, using real-time PCR, increased relative expressions of P450 aromatase and SF-1 genes were observed. The results demonstrate for the first time that MC-LR could induce toxicity in the male reproductive system of R. nigromaculata. The findings in this research will provide more insights into the relationships between aquatic microcystins and amphibians.
Department of Environmental Sciences, Hangzhou Normal University, Xiasha Gaojiao Dongqu, Zhejiang Province, China.
Hangjun
H
Zhang
Chenchen
C
Cai
Yingzhu
Y
Wu
Binhui
B
Ye
Li
L
Han
Xiaolu
X
Shou
Mengdi
M
Wang
Jia
J
Wang
Xiuying
X
Jia
D000818:Animals; D004789:Enzyme Activation / Q000187:drug effects; D004798:Enzymes / Q000378:metabolism; D005786:Gene Expression Regulation / Q000187:drug effects; D005837:Genitalia, Male / Q000187:drug effects*; D008297:Male; D008315:Malondialdehyde / Q000378:metabolism; D008387:Marine Toxins; D052998:Microcystins / Q000633:toxicity*; D046529:Microscopy, Electron, Transmission; D011898:Ranidae; D017382:Reactive Oxygen Species / Q000378:metabolism; D012708:Sertoli Cells / Q000187:drug effects; D013094:Spermatozoa / Q000187:drug effects; D014874:Water Pollutants, Chemical / Q000633:toxicity*
D004798:Enzymes; D008387:Marine Toxins; D052998:Microcystins; D017382:Reactive Oxygen Species; D014874:Water Pollutants, Chemical; D008315:Malondialdehyde; C057862:cyanoginosin LR