【摘要】 [目的]研究δ-氨基乙酰丙酸脱水酶(ALAD)基因多态性对职业铅接触工人甲状腺激素水平的影响。[方法]采集171名上海市某蓄电池厂职业铅接触工人外周静脉血样,用放射免疫测定法(RIA)测定工人甲状腺激素水平,包括T3、FT3、T4、FT4和TSH。聚合酶链反应-限制性片段长度多态性(PCR-RFLP)对ALAD基因进行分型分析,限制性内切酶为MspⅠ,并分析甲状腺激素水平与ALAD基因型的关系。[结果]171名工人中ALAD1-1纯合子基因型工人156名,基因型频率为91.23%;ALAD1-2杂合子基因型工人15名,基因型频率为8.77%;未检测出有ALAD2-2纯合子基因型工人。等位基因ALAD1和ALAD2的频率分别为95.61%和4.39%。协方差分析,ALAD1-2基因型工人PbB水平为1.06(0.87~1.24)μmol/L,明显比ALAD1-1基因型工人PbB水平0.77(0.72~0.83)μmol/L高,(F=8.14,P<0.05)。高血铅组工人(PbB≥0.97μmol/L)与低血铅组工人(PbB<0.97μmol/L)相比,甲状腺激素中除了FT4水平略有升高以外,T3、FT3、T4和TSH均是高血铅组工人低于低血铅组工人。ALAD1-2基因型组工人和ALAD1-1基因型组工人相比,T3、FT3和TSH的水平下降比较明显,而T4和FT4水平没有很大差异或是略有升高。低血铅组和高血铅组,都是ALAD1-2基因型工人的T3、FT3和TSH比ALAD1-1基因型工人的低,而T4和FT4的平均水平差不多或是略有升高。[结论]ALAD2等位基因可使工人体内血铅水平增高,增加体内铅负荷;在相同铅负荷下,ALAD2等位基因有加重铅对工人甲状腺功能影响的趋势,但需要扩大样本量进行验证。更多还原

【Abstract】 [Objective] To explore the effect of δ-aminolevulinate acid dehydratase( ALAD)gene polymorphism on hormone levels of thyroid in workers occupationally exposed to lead.[ Methods] 171 occupationally lead exposed workers in a storage battery factory were investigated. Thyroid hormones were detected by radioimmunoassay( RIA), including triiodothyronine( T3), free triiodothyronine( FT3), thyroxin( T4), free thyroxin( FT4) and thyroid-stimulating hormone( TSH). Polymorphism genotype of ALAD gene was determined by PCR-RFLP technique with the restriction enzyme Msp Ⅰ . The relationship between thyroid hormone levels and ALAD polymorphism was analyzed. [ Results] Among these 171 workers, there are 156 ALAD1-1 homozygotes (91.23%), 15 ALAD1-2 heterozygotes( 8.77%) and no ALAD2-2 homozygotes. The frequencies of ALAD1 and ALAD2 alleles are 95.61% and 4.39%. The PbB level of ALAD1-2 heterozygotes is1.06(0.87~1.24)μmol/L,which is significantly higher than that of ALAD1-1 homozygotes 0.77(0.72~0.83) μmol/L( F=8.14, P < 0.05), analyzed by analysis of covariance. Thyroid hormone levels of high PbB group( PbB≥0.97 μmol/L ) are compared with those of low PbB group( PbB < 0 .97 μmol/L), the results showed that T3,FT3,T4 and TSH depressed, FT4 elevated a little. The levels of T3,FT3 and TSH of ALAD1-2 subgroup are lower than those of ALAD1-1 subgroup, but there is no difference of T4 and FT4 in these two subgroups. In the two PbB subgroups, the levels of T3,FT3 and TSH of ALAD1-2 heterozygotes are both lower than that of ALAD1-1 homozygotes, but the levels of T4 and FT4 have no difference.[ Conclusions] ALAD2 allele could increase occupationally lead-exposed workers’ blood lead level and lead body burden. In the same occupational workplace and blood lead levels, ALAD2 allele might aggravate lead toxicity on thyroidhormones, which needs to be confirmed in coming study with larger sample sizes.更多还原