Selective effect of chronic lead ingestion. II: Effect on phenylethanolamine N-methyltransferase activity in brain regions of rats.
Selectivity of lead effect to phenylethanolamine N-methyltransferase (PNMT) activity in regions of brain from rats postnatally exposed to lead was tested. Three groups of animals were prepared; (1) Rats exposed to lead at a low dose (0.05% PbAcetate: PbAc); (2) Rats exposed to lead at a high dose (0.2% PbAc); (3) Age-matched normal control rats. At 2, 4, 6 and 8 weeks of age weight of whole brain and body in each group were measured. At the same ages activities of PNMT and Na+/K(+)-ATPase were examined on 4 brain regions of each animal. Exposure of rats to lead generally decreased activity of Na+/K(+)-ATPase and showed alternative change of those of PNMT. Brain regions where changes of PNMT activity were detected without concomitant changes of Na+/K(+)-ATPase activity, were telencephalon and pons/medulla at 2 weeks of age and telencephalon at 4 weeks of age in rats exposed to lead at a low dose, and those in rats exposed to lead at a high dose were pons/medulla at 8 weeks of age. These data imply that adrenergic nervous system in the brain regions described above could selectively be affected by lead.
Chin
K
K
National Institute of Safety Research, Seoul, Korea.
Lee
C J
CJ
Seo
K O
KO
Ko
K H
KH
Kuroiwa
Y
Y
D000367:Age Factors; D000818:Animals; D001921:Brain / Q000187:drug effects* / Q000201:enzymology; D004305:Dose-Response Relationship, Drug; D007854:Lead / Q000633:toxicity*; D010625:Phenylethanolamine N-Methyltransferase / Q000187:drug effects / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D000254:Sodium-Potassium-Exchanging ATPase / Q000187:drug effects / Q000378:metabolism
D007854:Lead; D010625:Phenylethanolamine N-Methyltransferase; D000254:Sodium-Potassium-Exchanging ATPase