Cellular zinc accumulation in anencephaly and spina bifida

Cultured skin fibroblasts were established from three newborns with NTDs (2 with anencephaly, one with SB), a 12-year-old with SB and three controls. Cells were plated at confluent densities and incubated with 65ZnCl2 for 2, 6, and 24 hours, or at subconfluent densities for 1-7 days. Radioactivity and DNA were determined in whole cell sonicates. Zinc uptake by confluent NTD cells was similar to controls at 2 hours, but was lower at 24 hours (p less than 0.001). In subconfluent cultures in log-phase growth, NTD cells accumulated greater amounts of zinc per microgram DNA than a control at 2-4 days (p less than 0.001) but did not differ at 1 and 7 days. Decreased zinc uptake in static cultures, and increased zinc accumulation in growing cultures, suggest that one or more cellular defects of zinc bioavailability may contribute to the pathogenesis of NTDs in some patients.