| Located in the eastern margin of Qinghai-Tibet Plateau, Zoige Wetland is a typical represent of alpine wetland ecosystems.But recently, the structure and function of this ecosystem is declining as results of global warming, temperature rise, plateau uplift, water level dropped and Zoige widespread over-grazing phenomenon, especially the abnormal population increasing of plateau pika (Ochotona curzoniae).It is reasonable for plateau pika to become a major vermint in grassland ecosystems, which exacerbats its degradation.In this study,α-chlorohydrin (a-chlorohydrin, ACH) was administered to plateau pikas.The ACH effect on plateau pikas toxicity, physiology, biochemistry, male reproductive system structure and function was detected by the methods of sperm counting, HE staining, observation of lectron microscopy and electrochemiluminescence immunoassay.From the study,suitable dose of ACH will be choosed to control the amount of plateau pikas in order to protect the grassland ecosystem.In order to meet the requirements of following-up experiments, ways to detect ACH on the plateau pika LD50 was determined according to The People's Republic of China Pesticide Registration toxicological test method (GB15670-1995). The results show the acute oral median lethal dose of ACH on plateau pika is 103.16mg/kg.While 95% confidence limit of LD50 is 75～124.09mg/kg,the average confidence interval LD50 is 103.16±19.17mg/kg. Based on the above results and the oral toxicity grading criteria, ACH was assessed to be poisoning to plateau pikas according to the acute pesticides.Udder the experimental results of LD50, ACH was disposed to different concentrations of 1/2LD50,1/4 LD50 and 1/8LD50 then was administered to male sexual maturity plateau pikas in dose of weight by 0.2mL/10g.Pikas was sacrificed after 19 days conventional breeding.Indexes of bodyweight, testis and epididymis, sperm count, vitality and deformity rate, serum testosterone, lactate dehydrogenase-C4 and total protein content were tested. Besides, both histopathological and ultrastructural of the testis and epididymis and anti-fertility effect on plateau pika were observed. Consequencely, ACH have very significantly reduced the number, vitality and motility of sperm in the plateau pika (P<0.01), with contrast of a significant increase in the rate of sperm deformity (P<0.01). Otherwise the sperm rumples rate has been a significant increased by the ACH increasing dose (P<0.01). However, plateau pika weight, testis and epididymis weight were not affected.ACH have a very significant effect on the plateau pika serum testosterone, lactate dehydrogenase-C4, and total protein (P＜0.01). Index of testosterone incrased from 1.38 ng/mL to 4.40 ng/mL, while LDH-C4 decreased from 2006.80U/L to 866.20U/L and total protein decreased from 74.37g/L to 49.40g/L. This indicates ACH has a significant influence on the growth and development. It also can be indicated from the histopathological and electron microscopy that ACH can significantly reduce the sperm number in epididymal sperm tube,hold up the development of spermatogenic cells, and increase the number of secondary spermatocytes considerably. Seminiferous tubule wall became significantly thicker, and the number of cytolysosome in spermatocyte increased.This experiment of ACH on the plateau pika anti-fertility effect confirmed that ACH can significantly reduce the female plateau pika vivi-fetus rate, from an average of 4.4 merely per fetus to 1.05. In addition,the number of early deaths and late fetal death of embryos increased significantly with increasing ACH dose,from an average of 0.15 per fetus and 0.15 to 2.55 and 1.25. This study confirmed that 60mg/kg can be a reference dose of ACH to control the amount of plateau pikas in wild.
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