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

AX5-24
Subject
Rat, F344,
male
Exposure
Protocol
2 or 10 mg/kg Pb(Ac) 2
Rat, LE, male 100 or 350 ppm Pb(Ac) 2
in dam’s water PND 0–21
Rat, LE, male 50 or 150 ppm Pb(Ac) 2
from weaning
Table AX5-3.4 (cont’d). Summary of Key Studies on Neurobehavioral Toxicity
Peak Blood Pb
or [Pb] Used Observed Effects Reference
2 mg: 23; 10 mg:
42 (adult),
~48 (old),
~58 µg/dL
(young)
Aging caused impaired accuracy: In both young and old rats: Pb-induced
increase in accuracy, at the longest delay periods (12 s) in young rats, and at the
short delay periods in old rats. Adults: not affected by Pb exposure.
Cory-Slechta
et al. (1991)
34 µg/dL Induced functional D2-D3 supersensitivity to the stimulus properties of agonist. Cory-Slechta
et al. (1992)
C Altered cholinergic sensitivity due to Pb and several agonists. Cory-Slechta and
Pokora (1995)
Rat, LE, male 50 or 150 ppm Pb(Ac) 2 35.7 µg/dL Postweaning Pb exposure resulted in an MK-801 subsensitivity. Cory-Slechta
(1995)
Rat, LE, male 50 or 150 ppm Pb(Ac)2
in water PND 21-use
Rat, LE, male 50 or 150 ppm Pb(Ac) 2
from weaning
Rat, LE, male 100 or 350 ppm Pb(Ac)2
from weaning
Rat, LE, male 50 or 500 ppm Pb(Ac) 2
from weaning
Rat, LE, male 50 or 500 ppm Pb(Ac) 2
from weaning
30.6 µg/dL (1) Enhances the stimulus properties of NMDA via a possible
dopaminergic path.
(2) Low level Pb exposure is associated with D1 subsensitivity.
15–25
30–50 µg/dL
Pb exposures attenuated the decrements in rates produced by the two D1 agonists SKF38393 and SKF82958, and at 150 ppm, Pb exposure altered the
rate change associated with the low dose (0.033 mg/kg) of quinpirole.
Cory-Slechta
et al. (1996a,c)
Cory-Slechta
et al. (1996b)
35.0 µg/dL Post-washout decrease in sensitivity to MK-801. Cory-Slechta
(1997)
49.1 µg/dL Increases FI schedule-controlled behavior in nucleus accumbens. Cory-Slechta
et al. (1998)
49.1 µg/dL Both DA and EEDQ, microinjected into the dorsomedial striatum, caused
increases or decreases in FI response rates, which depended on baseline FI
overall rates.
Cory-Slechta
et al. (2002)