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

AX5-68
Reference
Lai et al.
(2002)
Chang et al.
(2005)
Table AX5-5.3 (cont’d). Studies of the Effects of Lead Exposure on Blood Pressure and Adrenergic System
Species/
Tissue
Pb Exposure Measured Parameters
Age/
Weight n Dosage Duration Pb Level CVS Other Interventions Results
Male SD rats 300 g Acute
response
Male Wistar
rats
In vivo:
Intrathecal
injection of
PbCl2, 10–
100 µM.
In vitro:
Thoracic cord
slices exposed
to 5–50 µM
PbCl2
10 wks 70 2% Pb acetate
(drinking
water)
— — BP, HR, (In vivo)
w/without
ganglionic blockade
(Hexomethonium)
2 mo,
observed for
7 mo after
cessation
Blood:
85 µg/dL
Aorta:
8 µ/g/g
Heart:
1 µg/g
Kidney:
60 µg/g
Electophysiologi
c measures (In
vitro)
before/after
saline washout
BP Plasma NE, β
recaptor density
(aorta, heart,
kidney)
— In vivo: IT injection
of PbCl2 raised BP
and HR. This was
reversed by ganglionic
blockade. In vitro: Pb
raised excitatory and
lowered inhibitory
postsynaptic potentials
which were reversed
by removal of Pb
(saline washout)
Cessation of Pb
exposure
Pb exposure raised
BP, plasma NE, and
renal tissue β receptor
and lowered
aorta/heart β receptor
density. Plasma and
tissue Pb fell to nearcontrol
values within 7
mo. after Pb cessation.
This was associated
with significant
reductions (not
normalization) of BP,
plasma NE and partial
correction of tissue β
receptor densities
(Bone Pb was not
measured).