孕期激素对后代大鼠脑发育的影响

目的通过对妊娠期孕鼠产前应用不同疗程糖皮质激素(GCs),研究后代仔鼠脑组织重量、含水量及糖皮质激素受体的表达,了解孕期使用糖皮质激素对后代脑发育的影响。方法孕鼠于怀孕第18天开始每天肌注地塞米松0.48 mg/(kg·次),q4 h一次,4次为一疗程,连用3 d;单疗程后期与对照组以同等容积生理盐水代替。仔鼠生后第1天(P1)、P3称脑重,用干湿法测脑含水量;于P3、P7、P42用ISH法测量糖皮质激素受体mRNA在脑海马部位的表达。结果仔鼠胎儿期应用激素后脑重减轻,脑组织含水量却无改变,糖皮质激素受体表达下调。结论胎儿时期使用过量糖皮质激素影响仔鼠脑发育。

.The effects of brain development after antenatal glucocorticoids in neonatal rat

Objective To investigate the brain weights and the water contents of brain tissue, and the levels of GR mRNA in hippocampus after antenatal dexamethasone in neonatal rats. Methods We had given intramuscular dexamethasone to pregnant rats （0.48 mg/kg·time） after 18 days gestation, q·4 h, a course contains four doses, for three courses. Single course group and control group received equivalent volume of sterile saline. On the first day and the third day after birth （P1,P3）, we recorded the brain weights and the water contents of brain tissue. We also measured the expressions of glucocorticoid receptor mRNA on P3, P7, P42 in rats brain hippocampus. Results In the repeated courses group, the brain weights of neonates were decreased; The water contents of brain tissue were unchanged; The expression of glucocorticoid receptors were down-regulated. Conclusion Repeat GCs exposure in antenatal could have effects on the brain development of neonatal rat.