Abstract
The impact of low level lead exposure on human central nervous system function is a major public health concern. This study addresses the inhibition of the cation pump enzyme Na,K-ATPase by low level lead. Human brain tissue was obtained at autopsy and frozen until use. Brain homogenates were preincubated with PbCl2 for 20 min at 0° C. Inhibition of K-paranitrophenylphosphatase (pNPPase), a measure of the dephosphorylation step of Na,K-ATPase, reached steady state within 10 min. K-pNPPase activity, expressed (mean ± SEM) as a percentage of control (45.2±2.7 nmol/mg/min), fell to 96.3±0.9%at 0.25 uM [PbCl2] to 82.0±1.6% at 2.5 uM [PbCl2] in homogenates prepared from normal brain. Similar results were obtained with homogenates prepared from brains of patients with a history of alcohol abuse and of those with other miscellaneous conditions. Since the mean blood level of lead in the United States has ranged recently from 9.2 to 16.0 ug/dl (0.44 to 0.77 uM), these results indicate that current in vivo levels of lead exposure may impair important human brain function.
Original language | English (US) |
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Pages (from-to) | 2149-2156 |
Number of pages | 8 |
Journal | Life Sciences |
Volume | 48 |
Issue number | 22 |
DOIs | |
State | Published - 1991 |
Externally published | Yes |
ASJC Scopus subject areas
- General Pharmacology, Toxicology and Pharmaceutics
- General Biochemistry, Genetics and Molecular Biology