β-胡萝卜素对^(60)Co-γ辐射诱发的大鼠T-淋巴细胞次黄嘌呤鸟嘌呤磷酸核糖转移酶位点突变影响

Effect of β-carotene on 60~ Co γ induced mutation at T-lymphocyte hypoxanthine guanine phosphoribosyl transferase locus in rats

目的：研究β胡萝卜素（βＣａｒ）对电离辐射诱导的突变的影响．方法：Ｔ淋巴细胞克隆检测法测定大鼠Ｔ淋巴细胞次黄嘌呤鸟嘌呤磷酸核糖转移酶（ＨＧＰＲＴ）位点的突变率和硫代巴比妥酸（ＴＢＡ）法测定大鼠血丙二醛（ＭＤＡ）．结果：６０Ｃｏγ３７５Ｇｙ照射大鼠显著提高ＨＧＰＲＴ位点突变频率，ｉｇβＣａｒ１０和２０ｍｇ·ｋｇ－１，突变频率明显降低（Ｐ＜００５），应用βＣａｒ５ｍｇ·ｋｇ－１变化不甚显著，表现一定的剂量依赖性，同时βＣａｒ也明显降低６０Ｃｏγ诱发的大鼠血中ＭＤＡ水平（Ｐ＜００５）．ＭＤＡ下降水平与ＨＧＰＲＴ位点突变频率降低呈明显正相关性（ｒ＝０９９７８，Ｐ＜００５）．结论：βＣａｒ具有抗电离辐射诱导的突变作用，且这一作用与其抗氧化作用有关．

IM: To study the effect of β carotene (β Car) on radiation induced mutation. METHODS: Mutant frequency at T lymphocyte hypoxanthine guanine phosphoribosyl transferase (HGPRT) locus in rats was measured using a T lymphocyte cloning technique and malondialdehyde (MDA) was measured using a thiobarbituric acid (TBA). RESULTS: Mutant frequency at the HGPRT locus was elevated by 60 Co γ 3 75 Gy, and was reduced by ig β car 20 and 10 mg ·kg -1 ( P <0 05), but not by β Car 5 mg·kg -1 . It showed a dose dependent relationship. MDA was signifcantly reduced in plasma of rats given β Car after 60 Co γ radiation. There was positive coherence between MDA and mutant frequency at the HGPRT locus ( r =0 9978, P <0 05). CONCLUSIONS: Radiation induced mutation is inhibited by β Car, associated with antioxidant action of β Car.