产前应用地塞米松对早产仔鼠脑发育的影响

Objective To explore the effects of different courses of antenatal dexamethasone on brain development of premature SD rats. Methods The pregnant rats were randomly assigned to 3 groups: 3-dose dexamethasone (group 1), 1-dose dexamethasone group (group 2) and control group. The treated were sacrificed on 19 days of gestation, body and whole brain weight of the offspring rats were measured. Meanwhile the expression o{ neuron specific enolase (NSE) in brains of offspring rats was detected by immunohistochemical staining. The histological structures of baby rat brain were observed under transmission electron microscope. The differences among the three groups were analyzed by ANOVA. Results (1) The body and whole brain weight, the brain and body weight ratio were (1.543±0.052) g, (88.80±7.12) mg, and (5.75±0.38)% in group 1 and (1.584±0.035) g,(98.21±3.71) mg, and (6.20±0.26)% in group 2, both were lower than the control group (1.696±0.076) g, (111.53±6.29) mg, (6.59±0.48)%], (P<0.01 or P<0.05, respectively). (2) The expression of NSE in cortex in group 1 and 2 were lower than that in control group (0.223±0.054, 0.381±0.041 vs 0.590±0.064) (P<0.01). The expression of NSE in hippocampi in group 1 and 2 were also lower than that in the control group (0.192±0.054, 0.359 ±0.046 vs 0.529±0.068) (P<0.01). (3) Disconnection of nuclei membrane, vacuolization in mitochondria, loss of nueleolus, and disconnection of neurofilaments were observed in the ultrastructure of baby rat brain tissue in both group 1 and 2. Conclusions Antenantal administration of dexamethasone can cause impairment of brain development in premature offspring rats and this might be related to the times of dexamethasone administered.

Influences of antenatal administration of dexamethasone on brain development of premature offsprings in SD rats