红细胞嘧啶5′-核苷酸酶(P 5 N)是一种催化嘧啶5′-核糖-磷酸(即尿嘧啶和胞嘧啶5′-磷酸UMP和CMP)水解脱磷酸的酶。最近Mohammed-Brahim发现铅可抑制P 5 N的活性,但在职业性接触镉和汞的工人中,该酶並没有受到抑制,提示红细胞P 5 N可作为铅接触的特异性指标。选择77名职业性接触铅的男性工人(45±10岁),分别从事生产铅管、铅板、聚氯乙烯 Red cell cytosine 5’-nucleotidase (P 5 N) is an enzyme that catalyzes the hydrolysis of dephosphorylated pyrimidine 5’-ribose-phosphate (ie uracil and cytosine 5’-phosphate UMP and CMP). Mohammed-Brahim recently found that lead inhibits P 5 N activity, but was not inhibited in workers exposed to occupational exposure to cadmium and mercury, suggesting that red blood cell P 5 N may serve as a specific indicator of lead exposure. A total of 77 male workers (45 ± 10 years) with occupational exposure to lead were selected to produce lead pipes, lead plates, polyvinyl chloride