Effects of low-level lead exposure on cell survival and neurite length in primary mesencephalic cultures

The effects of low-level lead exposure on survival and neurite length of rat E15 primary ventral mesencephalic dopaminergic neurons were studied. Lead acetate (0.001 - 10 muM) added to primary cultures for 48 h (in serum-free defined media [DM]) caused a loss of tyrosine hydroxylase (TH)-positive neurons only at the highest concentrations (I and 10 muM). In contrast, significant effects on neurite length were observed at concentrations as low as 0.001 muM. Lead-induced decrease in neurite length became more apparent at concentrations of 0.01 mum (mean 37.9% decrease) and 0.10 muM lead acetate (mean 43.9% decrease). These data show that very low concentrations of lead, well below the level necessary to adversely affect neuronal survival, can have dramatic effects on neurite growth. These results support recent clinical findings of detrimental effects of low-level lead exposure on brain development. (C) 2003 Elsevier Science Inc. All rights reserved.