An In Vitro Assay For Teratogenic Organic Contaminants In Drinking Water With Micromass Rat Embro Midbrain And Limb Bud Cells

Objects: The purpose of this study was to screem quickly the positive teratogenic contaminants which were extracted from raw drinking water and tap water in Hefei city,Anhui province.An in vitro short-term test was carried out.Method:Organic contaminants from drinking water were extracted by use of XAD-4 macroreticular resins,and the procedure including column extraction,elution ,drying and concentration of eluate.With cultures of rat embryo limb bud cells for 5 days,the concentration inhibiting differentiation by 50% control(ID50) and the concentration inhibiting proliferation by 50% control(IP50) and the ratio of IP50/ ID50 were gotten respectively by each inhibition curve.Result: The organic extractives inhibited not only the cells differention but the proliferation of limb bud cells .The ID50 for tap water were 363.1 ml/ml (-S9)and 5. 7ml/ml (+S9); IP50 were 1355. 2ml/ml (-S9) and 1264. 5ml/ml (+S9), the ratios for IP50/ID50 (-S9)was 3. 7; IP50/ ID50(+S9)was 223 respectively; The ID50 for raw water were 1.2ml/ml (-S9) and 0. 387ml/ml (+S9); IP50 were 15.8ml/ml (-S9) and 41. 1ml/ml (+S9) , the ratios for IP50/ID50 (-S9) was 13.5; IP50/ ID50 (+S9) was 106.2 respectively. The organic extractives inhibited not only the cells differention but the proliferation of midbrain cells.The ID50 for tap water were 149.5 149.5 ml/ml (-S9) and 17. 2ml/ml(+S9); IP50 were >2200ml/ml (-S9) and 31. 2ml/ml (+S9) , the ratios for IP50/ID50 (-S9) was 14.7; IP50/ ID50 (+S9) was 1. 8 respectively; The ID50 for tap water were 2.36ml/ml (-S9) and 0. 87ml/ml (+S9); IP50 were 6.89ml/ml (-S9) and 26ml/ml (+S9) , the ratios for IP50/ID50 (-S9) was 2. 9; IP50/ ID50 (+S9) was 29. 9 respectively. This paper also suggested the extractives could be bioactivated into stronger inhibitors.Conclusion:These parameters indicated the influence of organic contaminants in drinking water on differentiation of rat midbrain cells was stronger than on proliferation,and those organics in drinking water belonged to a teratogenic agent and a specific inhibitors.The chlorination of drinking water should be studied more extently.