Lead: male-mediated effects on reproduction and development in the rat

The present study was designed to determine the effect of relatively low levels of lead acetate (25 and 250 ppm) exposure on fertility and offspring viability in male Sprague-Dawley rats. Protein synthesis in 2-cell embryos was monitored by [35S] methionine labeling and two-dimensional SDS gel electrophoresis. Fertility was reduced in males with blood lead levels in the range 27-60 microg/dL. Lead was found to affect initial genomic expression in embryos fathered by male rats with blood lead levels as low as 15-23 microg/dL. Dose-dependent increases were seen in an unidentified set of proteins with a relative molecular weight of approximately 70 kDa (Mr). These results indicate that male-mediated effects of lead may be observed in the 2-cell embryo. The alteration observed in embryonic gene expression with paternal lead exposure may be useful for studying the role of the paternal contribution to the activation of the embryonic genome and protein synthesis in the early embryo.