The effect of lead exposure and serum deprivation on mesencephalic primary cultures.
The effect of Pb2+ was studied in embryonic mesencephalic primary cultures that contain neurons and glia. Pb2+ exposure in absence of serum, damaged more efficaciously the cultured cells than Pb2+ exposure in presence of serum. In serum-free medium, Pb2+ elicited mainly necrosis and apoptosis in maximally 13% of the cells in culture. The glial fibrillary acidic protein (GFAP) content was decreased by Pb2+ exposure in serum-containing medium. The abundance of GFAP was also decreased by serum deprivation that was augmented by the addition of 12.5 microM Pb2+ in serum-free medium. A 6h exposure to 6 microM Pb2+ in serum-free medium also lowered the low affinity 3H-D-aspartate uptake. A 6h exposure of mesencephalic cells to 3-25 microM Pb2+ in serum-free medium failed to alter the number of tyrosine hydroxylase- and calretinin-immunoreactive cells, whereas, 50 microM Pb2+ obliterated both cell types. A 6h exposure of cells to 3 microM Pb2+ in serum-free medium decreased 3H-dopamine uptake by 50 % and 12.5 microM Pb2+ obliterated it. Addition of albumin to serum-free medium failed to prevent the Pb2+ -elicited inhibition of [3H]-dopamine uptake suggesting that the serum-afforded delay of cell death may not be due to a removal of reactive Pb2+ by protein/chelate formation but rather to the Pb2+ -scavenging function of glial cells. Serum deprivation may exacerbate the Pb2+ -induced neurotoxicity presumably by impairing the metal scavenging function of astrocytes.
Scortegagna
M
M
Laboratory of Molecular Immunology, NHLBI, Bethesda, MD 20892-1674, USA.
Hanbauer
I
I
D000818:Animals; D001224:Aspartic Acid / Q000378:metabolism; D064032:Calbindin 2; D016923:Cell Death / Q000187:drug effects; D002478:Cells, Cultured; D016895:Culture Media, Serum-Free; D004298:Dopamine / Q000378:metabolism; D005904:Glial Fibrillary Acidic Protein / Q000378:metabolism; D015151:Immunoblotting; D007150:Immunohistochemistry; D007854:Lead / Q000378:metabolism; D007855:Lead Poisoning / Q000378:metabolism / Q000473:pathology*; D008636:Mesencephalon / Q000166:cytology* / Q000378:metabolism; D009419:Nerve Tissue Proteins / Q000378:metabolism; D010084:Oxidation-Reduction; D010641:Phenotype; D010751:Phosphopyruvate Hydratase / Q000378:metabolism; D011485:Protein Binding; D051381:Rats; D017207:Rats, Sprague-Dawley; D064030:S100 Calcium Binding Protein G / Q000378:metabolism
C576512:Calb2 protein, rat; D064032:Calbindin 2; D016895:Culture Media, Serum-Free; D005904:Glial Fibrillary Acidic Protein; D009419:Nerve Tissue Proteins; D064030:S100 Calcium Binding Protein G; D007854:Lead; D001224:Aspartic Acid; D010751:Phosphopyruvate Hydratase; D004298:Dopamine