RESUMO
Objective To research the estrogen-like activity of the DDTs and the extract of vehicle exhaust by recombinant yeast system.Methods Being added into the yeast cell culture fluid,the objects reached the final concentration of 10-9～10-15 mol/L for 17?-estradiol,10-4～10-9 mol/L for DDTs(p,p'-DDT,o,p'-DDT,p,p'-DDD,p,p'-DDE),0.25～8.00 ml/ml for the extract of vehicle exhaust,then the cultivation was performed for 4 hours,the quantitative assay of ?-galactosidase activity accounts for the estrogenlike effect of the samples was carried out.Results DDTs were a group of environmental estrogens hormones,which could integrate estrogen receptors as the stimulators do and express the estrogen-like effect.Being tested separately,the DDTs showed the estrogen-like activity,which was stronger for o,p'-DDT and weaker for p,p'-DDE.The?-galactosidase activity of gasoline-fueled vehicle exhaust at the final concentration of 2.00～4.00 ml/ml was significantly different from that of the DMSO(P