13.02.2013 Views

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

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

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

SHOW MORE
SHOW LESS

Create successful ePaper yourself

Turn your PDF publications into a flip-book with our unique Google optimized e-Paper software.

AX5-135<br />

Table AX5-8.3 (cont’d). Bone Cell Cultures Utilized to Test Effects <strong>of</strong> <strong>Lead</strong><br />

Compound<br />

Dose/Concentration<br />

Duration Exposure<br />

Route Species Effects Blood Level Reference<br />

Pb acetate<br />

0.1 to 30 µM<br />

24 h<br />

In medium<br />

Abbreviations<br />

Chicken<br />

growth plate<br />

and sternal<br />

chondrocytes<br />

Pb—lead<br />

µCi—microCurie<br />

IU—international units<br />

hr—hour<br />

OB—osteoblast<br />

5F-BAPTA—1,2-bis(2-amino-5-fluorophenoxy)ethane-N,N,N’,N’-tetraacetic acid<br />

[Pb 2+ ]i—free intracellular lead<br />

FURA-2—1-[6-Amino-2-(5-carboxy-2-oxazolyl)-5-benz<strong>of</strong>uranyloxy]-2-(2-amino-5methylphenoxy)<br />

ethane-N,N,N',N'-tetraacetic acid<br />

M—molar<br />

DNA—deoxyribonucleic acid<br />

∆M—decrease in magnetization <strong>of</strong> intracellular Pi upon prolonged saturation <strong>of</strong> gammaphosphate<br />

<strong>of</strong> ATP<br />

mM—millimolar<br />

Kcat—activation constant<br />

IC50—inhibitory concentration 50%<br />

mg—milligram<br />

210<br />

Pb—lead-210 radionuclide<br />

EM—experimental medium<br />

mU—milliunits<br />

45<br />

Ca—calcium-45 radionuclide<br />

CRAC—calcium release activated calcium reflux<br />

pg—picogram<br />

mRNA—messenger ribonucleic acid<br />

ng—nanogram<br />

A dose-dependent inhibition <strong>of</strong> thymidine incorporation into growth plate<br />

chondrocytes was found with exposure to 1–30 µM Pb <strong>for</strong> 24 h. A maximal 60%<br />

reduction occurred at 30 µM. Pb blunted the stimulatory effects on thymidine<br />

incorporation produced by TGF-β1 (24% reduction) and PTHrP (19% reduction),<br />

however, this effect was less than with Pb alone. Pb (1 and 10 µM) increased type X<br />

collagen in growth plate chondrocytes ~5.0-fold and 6.0-fold in TGF-β1 treated<br />

cultures and 4.2-fold and 5.1-fold in PTHrP treated cultures when compared with<br />

controls, respectively. Pb exposure alone reduced type X collagen expression by<br />

70–80%.<br />

Vmax—maximum velocity<br />

TGF-β1—trans<strong>for</strong>ming growth factor-beta 1<br />

mL—milliliter<br />

i.v.—intravenous<br />

CM—control medium<br />

µM—micromolar<br />

ng—nanogram<br />

[Ca 2+ ]i —free intracellular calcium<br />

PGE2—prostaglandin E2<br />

PKC—protein kinase C<br />

Kd—dissociation constant<br />

nmol—nanomole<br />

HOS TE 85 cells—human osteosarcoma cells<br />

PTHrP—parathyroid hormone-related protein<br />

GD—gestational day<br />

PTH—parathyroid hormone<br />

min—minute<br />

OC—osteoclast<br />

ROS 17/2.8—rat osteosarcoma cells<br />

nM—nanomolar<br />

h—hour<br />

IGF-I—insulin growth factor I<br />

ATP—adenosine triphosphate<br />

EGF—epidermal growth factor<br />

Not applicable Zuscik et al.<br />

(2002)

Hooray! Your file is uploaded and ready to be published.

Saved successfully!

Ooh no, something went wrong!