Lead, an environmental pollutant, has been long recognized as a neurotoxic agent. Several reports have recently described behavioral disturbances caused by low level exposure. Lead-induced changes in neurotransmitter metabolism in the brain may help to elucidate the molecular basis for the observed behavioral alterations. In this study, the influence of low level lead exposure on the hypothalamic expression of rat opioid genes was examined. Determination of relative opioid mRNA levels revealed a dramatic increase of pro-opiomelanocortin (POMC) mRNA concentrations in response to lead. This increase was found to be specific, developmentally regulated, reversible and dependent on prolonged lead exposure. These findings may provide substantial evidence for the possible connections between early environmental inputs and the expression of neuropeptide genes in the brain.
Bibliographical noteFunding Information:
We thank Drs. O. Civelli, J, Douglass, M. Uhler and (the late) E. Herbert for providing us with the p2RD2-19 and pMKSU16 plasmids. Supported by grants from the Charles H. Revson Foundation, The Israel Institute of Psychobiology and the Foundation for the Study of Molecular Virology and Cell Biology.
- Gene expression