Air Quality Criteria for Lead Volume II of II - (NEPIS)(EPA) - US ...

AX5-18
Subject Exposure Protocol
Rat
PND 21–adult
50 or 150 ppm Pb(Ac)2
water for 2 wks–8 mo
Adult rat Water—0.2% Pb(Ac) 2
from PND 0–adult
Rat
4 mo
Rat
PND 111
Water—0.2% Pb(Ac) 2
from GD 16 to PND 28
Table AX5-3.1 (cont’d). Summary of Key Studies on Neurochemical Alterations
Water at 50 ppm Pb(Ac)2
for 90 days; start at PND 21
Cultured bovine chromaffin cells Variable kind and
concentration
Peak Blood Pb or
[Pb] used Observed Effects Reference
28.0 µg/dL Differential effects in [ 3 H]MK-801 binding with dopamine and D 1
agonists.
Cory-Slechta et al.
(1997a)
37.2 µg/100 mL Presynaptic glutamatergic function in dentate gyrus is diminished. Lasley and Gilbert
(1996)
22.0 µg/dL Developmental Pb results in long-lasting hippocampal cholinergic
deficit.
Bielarczyk et al.
(1996)
18 µg/dL Decreases in vivo release of dopamine in the nucleus accumbens. Kala and Jadhav
(1995)
Exerts dual stimulatory and inhibitory effects on adrenal PKC. Tomsig and Suszkiw
(1995)
Rat Homogenized cortex Ranging Pb(Ac)2 Pb activates PKC in the range of 10 −11 to 10 −8 M. Long et al. (1994)
Rat
PND 14 or 56
Cultured bovine chromaffin cells Variable kind and
concentration
Neuronal membranes Chow containing
750 ppm Pb(Ac)2
Rat Cortical synaptosomes 1–50 nM free Pb
or 1 µM Pb(NO3) 2
Pb and calcium activate the exocytotic release of norepinephrine. Tomsig and Suszkiw
(1993)
Review paper discussing Pb-calcium interactions in Pb toxicity. Simons (1993b)
Review paper exploring Pb as a calcium substitute. Goldstein (1993)
Inhibitory effect on [ 3 H]MK-801 binding and loss of binding sites in
neonates.
Guilarte and Miceli
(1992)
Triggers acetylcholine release more effectively than calcium. Shao and Suszkiw
(1991)