Ong C N, Kong Y M, Ong H Y, Teramoto K
Department of Community Medicine, National University of Singapore, Kent Ridge.
Pharmacol Toxicol. 1990 Jan;66(1):23-6. doi: 10.1111/j.1600-0773.1990.tb00695.x.
The in vitro and in vivo effects of lead on the activity of pyrimidine-5'-nucleotidase (P5N, E. C. 3.1.3.5) and delta-aminolevulinic acid dehydratase (ALA-D, E.C. 4.2.1.24) were studied. Incubation of blood with lead at concentrations of up to 3 mumol/l (about 60 micrograms/dl) did not appear to affect the activity of P5N, while the activity of ALA-D decreased dose-dependently with lead. Administration of lead caused a marked and rapid suppression of ALA-D in rats. The suppression of lead on P5N appeared to be a rather slow process. The decrease of its activity only came into effect 20 days after administration with lead. these findings suggest that lead induced P5N inhibition is a slow process while the suppression of ALA-D activity occurs much earlier.
研究了铅对嘧啶-5'-核苷酸酶（P5N，E.C. 3.1.3.5）和δ-氨基乙酰丙酸脱水酶（ALA-D，E.C. 4.2.1.24）活性的体内和体外效应。用浓度高达3 μmol/l（约60微克/分升）的铅孵育血液似乎不会影响P5N的活性，而ALA-D的活性则随铅剂量依赖性降低。给大鼠投予铅会导致ALA-D明显且迅速地受到抑制。铅对P5N的抑制似乎是一个相当缓慢的过程。其活性降低仅在投予铅20天后才显现出来。这些发现表明，铅诱导的P5N抑制是一个缓慢的过程，而ALA-D活性的抑制则发生得更早。
