ABSTRACT
Objective To explore the effect of antenatal taurine supplementation on cerebral apoptosis and the expression of glial cell line-derived neurotrophic factor (GDNF) and caspase-3 in fetal rats with fetal growth restriction (FGR).Methods Fifteen pregnant Sprague-Dawley rats were randomly divided into three groups:control group,FGR model group (model group) and FGR with antenatal taurine supplementation group (taurine group).Taurine was added into the diet of taurine group at a dose of 300 mg/(kg · d) from the 12th day of gestation until natural delivery.Two appropriate for gestational age (AGA) newborn rats were randomly selected from each mother in control group and two FGR fetal rats were randomly selected from each mother both in model and taurine groups.Apoptosis of neural cells in the brain was detected by terminal deoxynucleotidyl transferase mediated nick end labeling (TUNEL).Changes in protein expression of GDNF and caspase-3 were detected by immunohistochemistry.Levene method,one-way ANOVA and SNK-test,or Kruskal Wallis rank sum test and Tamhane’ s test were applied for statistical analysis.Results (1)The total amounts of fetal rats in control group,model group and taurine group were 65,60 and 59.The mean body weight of fetal rats were (6.36±0.44) g,(4.55 ± 0.45) g and (5.11±0.67) g,respectively.All fetal rats developed FGR in model group,while 76.3％(45/59) of fetal rats were FGR in taurine group.Therefore,FGR model was successfully established.(2) In control group,there were few expression of TUNEL positive cells in cerebral cortex.A large amount of TUNEL positive cells were found in the cortex,hippocampal and white matter area in model group,but less positive cells were identified in taurine group than in model group.The amount of apoptotic brain cells in the three groups were (0.46 ± 0.11),(14.76 ± 3.42) and (6.78 ± 1.93),respectively(H=429.80,P=0.000).(3)There were only small amount of GDNF positive cells in cerebral cortex in control group and more in model group.The amount of GDNF positive cells was further increased in taurine group.The amount of GDNF positive cells in cerebral cortex in the three groups were (93.56± 6.73),(120.36± 6.23)and(139.56± 5.28),respectively (H=715.17,P=0.000).(4) Few caspase-3 positive cells were found in cerebral cortex in control group.A large amount of positive cells were found in model group and less positive cells were found in taurine group,which was still more than those in control group.The amounts of caspase-3 positive cells in the three groups were (7.50±2.31),(151.32±24.43)and(37.28±11.21),respectively (F=132.54,P=0.000).Conclusions The number of apoptotic neural cells in brain tissue of baby rats with FGR were significantly increased,which can be significantly alleviated by maternal antenatal taurine supplementation through upregulation of GDNF and downregulation of caspase-3 expression.