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

AX5-128
Table AX5-8.2 (cont’d). Regulation of Bone Cell Function in Animals—Systemic Effects of Lead
Compound
Dose/Concentration
Duration Exposure
Route Species Effects Blood Level Reference
Pb nitrate
0.02% (125 ppm)
GD5 to 1 day before
sacrifice
In drinking water
Pb acetate
0.05% to 0.45%
GD 5 through sacrifice
of pups at 21, 35, 55,
and 85 days
In drinking water
Abbreviations
mg—milligram
h—hour
1,25-(OH) 2CC—1,25-dihydroxycholecalcigerol
µg—microgram
25-OH D 3—25-hydroxycholecalciferol
PbCl2—lead chloride
1,25-(OH) 2 D 3—vitamin D 3
kg—kilogram
mg%—milligram percent
pg—picogram
Rat Basal release of growth hormone from control and Pb-exposed pups at age 49 days was not
significantly different. Growth hormone releasing factor-stimulated release of growth
hormone from pituitaries of Pb-exposed pups was smaller than the stimulated release of
growth hormone from pituitaries of control animals (75% increase over baseline vs. 171%
increase, respectively), but the difference did not achieve significance (P = 0.08). Growth
hormone content of the pituitary glands was also not influenced by Pb exposure.
Rat Pituitary GH content (µg/mg) at postnatal day 55:
Control Male Pups = 56.6 ± 8.0; Female Pups = 85.6 ± 9.3
0.05% Pb Male Pups = 107.2 ± 10.5*; Female Pups = 116.2 ± 9.1
0.15% Pb Male Pups = 96.8 ± 5.0*; Female Pups = 105.1 ± 7.3
0.45% Pb Male Pups = 106.0 ± 9.8*; Female Pups = 157.0 ± 9.9*
*significantly different from control, p < 0.05
GD—gestational day
mM—millimolar
Pb—lead
pM—picomolar
i.v.—intravenous
%—percent
mL—milliliter
dL—deciliter
mRNA—messenger ribonucleic acid
ppm—parts per million
GH—growth hormone
min—minute
Rat Pups
5 days old: 43.3 ±
2.7 µg/dL
49 days old: 18.9
± 0.7 µg/dL
(females: 19.94 ±
0.8 µg/dL; males:
17.00 ± 1.1 µg/dL)
Offspring:
0.05% Pb = 49 ± 6
µg/dL; 0.15% Pb =
126 ± 16 µg/dL;
0.45% Pb = 263 ±
28 µg/dL
Camoratto et al.
(1993)
Ronis et al.
(1998b)