Retardation of fetal brain cell growth during maternal starvation: circulating factors versus altered cellular response.

Maternal starvation inhibits fetal brain development during late gestation in the rat. To determine whether intrinsic or extrinsic factors might be the principal contributor to altered growth, brain cells from 20 day fetuses were cultured in a 96 well plate with MEM and 10% adult rat serum. Tissue growth was monitored by spectrophotometric measurement of the mitochondrial reduction of a chromagen 3-(4,5 dimethylthiazol-2-yl)-2,5 diphenyl tetrazolium bromide (MTT). After 1, 4 or 6 days incubation, MTT activity in non confluent cultures was shown to be directly related to tissue mass. When fetal brain cell cultures were incubated with 1% and 10% concentrations of adult rat serum, an 11-fold increase in MTT activity paralleled a 15-fold increase in tritiated thymidine incorporation. The impact of maternal starvation on fetal brain cell growth was examined by measuring MTT activity in fetal brain cells from fed and starved mothers. When cultures were incubated for 6 days with graded concentrations of fed adult serum (1.25-10%), the MTT response was slightly but consistently lower in cells from starved when compared with cells from fed mothers. By contrast, a marked difference in MTT activity which was paralleled by a lower DNA content became apparent when fetal rat brain cells were incubated with starved adult serum. Fetal serum and adult male serum were found to support growth equally well, while incubation of fetal brain cells with maternal sera resulted in lower MTT values than with the corresponding fetal sera. When cells were incubated with fetal sera pooled from starved mothers, MTT activity was decreased by 42 to 45%.(ABSTRACT TRUNCATED AT 250 WORDS)