| Since 1996, the effects of environmental estrogens on wild lives and human beings have attracted more and more attention of scientists in the world. Recently, several research plans of environmental estrogens were started in European Union, United States and Japan, and some in vitro and in vivo screening technology have been built up by now. But the previous research works mainly focused on the screening of environment persistent pollutants, such as organochlorine insecticides and alkylphenol, to our knowledge, no report on the residual toxicity and environmental estrogens effects has been existed in the literature yet. Since China is a big agricultural country and usually applies a large amount of organophosphorous pesticides every year, it is very necessary to do some relative research on the estrogen effects of organophosphorous. In this paper, we selected a widely used organophosphorous pesticide --monocrotophos, used goldfish as model animal, and chose the vitellogenin induction of male fish as the main indicator, -GTP of sertoli cell in testes, the changes of microstructures of testis and ultrastructures of pituitary and testis as assistant indicators, we finally built up a screening system to effectively detect the environmental estrogen effect of organophosphorous pesticides, and reported that the monocrotophos had the activity of environmental estrogen for the first time in the world.The vitellogenin in male goldfish was induced by 17/?-estradiol dissolved in ethanol (intraperitoneal injection, 0.05mg g-1BW). After two weeks induction, the blood was collected from caudal vessel, then centrifuged at 8,000 g for 5 min. After serum native-PAGE, the gel was stained with the method of CBB G250-, phospho-, lipo- and glyco-staining respectively. Then we identified the location of vitellogenin in the gel. This method provided a practical and effective way of vitellogenin identification. Theresults of native-PAGE showed that the male fish could synthesis vitellogenin after the injection of 0.05mg g"'BW of 17 -estradiol for two weeks. The average content of vitellogenin in Ej exposed group was 690.2ng ml-1 by ELISA, it was significantly different from male control group (p<0.01), which average content was 10.7 ng ml-1, and it was also much higher than the female control group, which average content was 285.5 ng ml-1. Compared with control male goldfish, both the Ca2+ content and total protein content in serum of the E2 exposed male goldfish showed significant increase.After exposing to 0.01, 0.1 and 0.5mg L-1 monocrotophos for 21 days, the inductions of vitellogenin in male goldfish were detected in all exposed group. By the method of ELISA, the vitellogenin contents were determined as 244.0, 833.1 and 479.5ng ml-1 respectively. The dose-response curve showed a reversed U-shape as long as the increasing concentration of monocrotophos, and the total protein contents in serum exhibited marked increase in all the three exposed groups.The damages of monocrotophos on tnicrostructure of testis were that it caused the deficiency of ground membrane, hypertrophied Leydig cell and spermatogenous. Besides, the Y -GTP activity was inhibited by monocrotophos. The results suggested that monocrotophos had not only environmental estrogen effects, but also reproductive toxicity.Monocrotophos could destroy the membrane systems of three kinds of pituitary secretary cell, spermatogenous cell and sperm. In three kinds of pituitary secretary cell, nuclear membrane and endoplasmic reticulum showed dilation, and endoplasmic reticulum even exhibited fusion under exposure in high concentration. In spermatogenous cell, we could find dilated cytolemma, dilated nuclear membrane and fused crista of mitochondria. Most of the sperm's cellular membrane dissolved and broke down into pieces. The central granule and mitochondrion showed little dissolving. The chromatin of Sertoli cell condensed tightly and formed some low electron density areas, nuclear membrane dissolved, the intercellular junction dilated.
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