苯并(a)芘代谢产物诱发BALB/3T3细胞程序外DNA合成的研究

Study on Unscheduled DNA Synthesis in BALB/3T3 Cells Induced by BaP Metabolites.

为了解苯并（ａ）芘（ＢａＰ）代谢产物对哺乳动物细胞ＤＮＡ的损伤作用，本实验采用单标记和双标记法，分别检测４种苯并（ａ）芘代谢产物（ａｎｔｉ－ＢＰＤＥ，ｓｙｎ－ＢＰＤＥ，３－ＯＨ－ＢＰ和９－ＯＨ－ＢＰ）对ＢＡＬＢ／３Ｔ３细胞ＤＮＡ合成和程序外ＤＮＡ合成（ＵＤＳ）的影响。结果表明：ａｎｔｉ－ＢＰＤＥ、ｓｙｎ－ＢＰＤＥ、３－ＯＨ－ＢＰ和９－ＯＨ－ＢＰ均在不同程度上使ＢＡＬＢ／３Ｔ３细胞ＤＮＡ合成增加；但只有ａｎｔｉ－ＢＰＤＥ、３－ＯＨ－ＢＰ和９－ＯＨ－ＢＰ可诱发ＢＡＬＢ／３Ｔ３细胞的ＵＤＳ。说明这些苯并（ａ）芘代谢产物可损伤ＢＡＬＢ／３Ｔ３细胞的ＤＮＡ，这种效应可能与苯并（ａ）芘代谢产物的立体结构有关。

In this study,damage effect of BaP metabolites on mammalian cell DNA was assessed.Four BaP metabolites(anti BPDE,syn BPDE,3 OH BP and 9 OH BP)were assessed for their potential to induce DNA synthesis and unscheduled DNA synthesis(UDS) in BALB/3T3 cells. BALB/3T3 cells were cultured with E9888 (arginine free medium) and treated with 14 C TdR (0.01μ Ci/ml) for 72 hrs ,subsequently with 3H TdR (1μ Ci/ml) and BaP metabolites for another 24 hrs.Radioactivity was measured with LS6000 liquid scintillation system .The results showed that all metabolites increased DNA synthesis but only anti BPDE,3 OH BP and 9 OH BP induced UDS.Anti BPDE induced UDS in a relatively high level,compared with 3 OH BP and 9 OH BP Syn BPDE is completely different from anti BPDE in stereo structure and may be not suitable to bind with DNA.It is suggested that DNA of BALB/3T3 cells could be damaged by BaP metabolites and DNA damage was related to stereo structure of BaP methabolites.