ABSTRACT
To investigate the effect of magnesium sulfate on the fetal rats of FGR and the expression of caspase-3 in the placenta of maternal rat; To explore the mechanism of using magnesium sulfate to cure the FGR. Establish model of FGR by a way of passive smoking: giving the maternal rats different agent of magnesium sulfate by subcutaneous injection: low agent group (300 mg/kg),high agent group (600 mg/kg). Concentration of magnesium sulfate was monitored. The expres sion of caspase-3 was measured by RT-PCR and immunohistochemistry technology. Both of the concentrations of magnesium sulfate in high and low agents group are higher than the FGR group (P＜0. 01); the weight of the placenta and fetal rat in high agent group are higher than the FGR group (P＜0.05 and P＜0.01); the expression of mRNA and protein of caspase-3 in the two agent group is higher than the FGR group (P＜0.05 respectively); concentration of magnesium sulfate in the maternal rat blood correlate to the weight of fetal rat (r=0. 899, P=0. 038) and the expression of caspase-3 in the placenta of maternal rat (r= 0.747, P 0.033; r=-0. 915, P=0.001).The research suggests that the weight of fetal rat could be increased by treatment of magnesium sulfate. Because it would imfrmove the placental function by depressing the expression of caspase-3.