title: The in vitro and in vivo effects of lead on delta-aminolevulinic acid dehydratase and pyrimidine 5'-nucleotidase.
abstract: 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.
authors.affiliation: Department of Community Medicine, National University of Singapore, Kent Ridge.
authors.forename: C N
authors.initials: CN
authors.lastname: Ong
authors.forename: Y M
authors.initials: YM
authors.lastname: Kong
authors.forename: H Y
authors.initials: HY
authors.lastname: Ong
authors.forename: K
authors.initials: K
authors.lastname: Teramoto
mesh_terms: D015720:5'-Nucleotidase / Q000096:biosynthesis* / Q000378:metabolism; D000818:Animals; D004912:Erythrocytes / Q000201:enzymology*; D006801:Humans; D007854:Lead / Q000097:blood / Q000494:pharmacology* / Q000633:toxicity; D008297:Male; D000623:Porphobilinogen Synthase / Q000096:biosynthesis* / Q000378:metabolism; D011897:Random Allocation; D051381:Rats; D011919:Rats, Inbred Strains
chemical_list: D007854:Lead; D015720:5'-Nucleotidase; D000623:Porphobilinogen Synthase