Studies On The Endocrine Disruption Toxicity And Genotoxicity Of PCP On Gobiocypris Rarus

Pentachlorophenol(PCP), which is one of the phenolie compounds,can interfere with the normal incretion function of animals,and it is also an important environmental hormone.Its chemical properties are relatively stable, it can accumulate in the sediments, and it is difficult to be degraded. So the residue in the environment is relatively high.When it had been widely used as soil insecticide throughout the world, it caused seriously environmental problem. At present in view of the fact that estrogen endocrine disturbance toxicity and the heredity toxicity of PCP to the aquatic environment and aquatic animal's harm, as well as the dispute which exists in these questions. In this paper, Rare Minnows as a bioindicator was chosen to assess the endocrine disruption effects of estrogen and genotoxicity of PCP on the levels of individual embryos, organs, cell and molecule levels,Which have provided the basic data for the establishment of a fast, effective, and practical biological monitoring and the test technology in vivo. The results show as follows:1.Rare Minnows were experimentally exposed to sublethal concentrations (10,40,80,120 and 160μg/L) of PCP and histopathological studies were conducted on gills, kidney, liver and gonads after 7,14,21, and 28 days. Epithelial hyperplasia, aneurism, epithelial necrosis, desquamation, epithelial lifting, oedema, shortening of secondary lamellae and lamellar fusion were observed in gill tissues exposed to PCP and EE2. Results show that pathological male liver was associated with a hypertrophy of hepatocytes, cloudy degeneration, karyolysis, karyohexis, and accumulated eosinophilic material. Kidney tissue showed different pathological effects such as accumulation of eosinophilic material, dilatation of glomerular capillaries, hypertrophied cells, narrowing of tubular lumen, and degeneration of glomerulus. Furthermore, under exposure of experimental concentrations, increment of developed primary spermatogonia, secondary spermatogonia, and testis-ova were noticed in male fish. In female, increment of previtellogenic oocyte and atresia of vitellogenic oocytes were seen. All the above results show that PCP exposure in adult rare minnow leads to significant histopathological changes, and suggest that the histopathological method could be a sensitive monitor for aquatic pollution.2.Take Vitellogenin (VTG) of adult rare minnow as biomarkers of the estrogen pollutant, and make the positive control to it with superactive synthetical diethylstilbestrol (EE2). Then estimate the estrogen effect of pentachlorophenol (PCP) with SDS-PAGE map and determine the molecular weight of adult rare minnow's Vitellogenin. The results indicated that:after the static state exposes 21d, the male fish in vivo produced microdosis VTG which deal with pentachlorophenol, but the female fish have no obvious changes. At last, determined the molecular weight of two subunits of yolk protein original (VTG) respectively is 120kDa and 103kDa.3. Using degenerate primers Rare Minnow VTG and part of p53 gene fragments, and contrasting entire gene sequence with zebra fish and other species of fish found the Similarity was in 93% and 80%. With this fragment, by real-timePCR technology, we studied estrogen endocrine effects and carcinogenicity on mRNA level of the PCP. The results show that, PCP could induce rare minnow liver VTG and the expression of p53 gene and showed marked dose-and time-effect relationship; However, compared with positive control EE2 induced a weak effect, indicating PCP endocrine disrupting effects of estrogen relatively weak. In summary, PCP hadn't only estrogenic properties and carcinogenic, but also that rare minnow VTG and p53 for environmental monitoring of EDCs as an ideal biomarker.4.By using the alkaline single cell gel-electrophoresis (SCGE), the DNA damage in blood cells and liver cells of Gobiocypris rarus caused by pentachlorophenol at different exposure time (1day,4days,7days) with different concentration of pentachlorophenol (40,100,160μg/L) was evaluated. Tail DNA percentage (%DNAT) and tail length (TL) of the three tested groups were significantly different from the control group (P< 0.05). Furthermore, the damage intensity of treated groups increased gradually with respect to the increasing of pentachlorophenol. The concentration-effect relationship was significant for the correlation coeffiencient was graeter than 0.926. Under the same concentration, the% DNAT and TL increased gradually with the time of exposure. The time-effect relationship was also significant. This study recommended that it could be a sensitive monitor of aquatic pollution to use the SCGE to detect the DNA damage in fish blood cells and liver cells. It showed that this assay could be applied in the assessment of water pollution and aquatic mutagens.5. By using Rare Minnow embryonic development technology, the toxicity of PCP in the embryo of Rare Minnow was evaluated. The results show that, the embryo development was significantly inhibited, and resulted in abnormal embryonic development or death caused by PCP at different exposure time with different concentration of pentachlorophenol was evaluated. Exposure at different time different toxicological endpoints was observed; with the increasing concentration of PCP effects, rare minnow embryo hatching rate, the relative survival rate decreased gradually increased malformation rate, showed a significant dose-response relationship. In summary, rare minnow embryo technology can be used as an endocrine disruptor toxicity indicator.