Objective:To explore the effects of intrauterine infection on early growth and neurobehavioral development in neonatal rats. Methods:Escherichia coli (E. coli) was inoculated into uterine cervix of pregnant rats with gestation of 15 d to establish the intrauterine infection model, and the effect on the delivery of pregnant rats was observed. The neonatal rat brain tissue was stained with Hematoxylin-Eosin and the cerebral white matter damage was assessed. Immunohistochemical staining and Western blot analysis were performed to evaluate the expression of glial fibrillary acidic protein (GFAP), 2', 3'-cyclic nucleotide 3'-phosphodiesterase (CNPase) and neurofilament (NF) in pup brains. Birth weight and early growth development indices were monitored,and neurobehavioral tests were performed to access the change of neurobehavioral development in neonatal rats. Results:The white blood cell count increased significantly in the uterus and placenta of the pregnant rats after intrauterine E. coli infection and no significant impact was observed on the delivery of pregnant rats. Weak staining and focal rarefaction of cerebral white matter from rats at P7 in intrauterine infection group were observed. The expression of GFAP markedly increased (P<0.05) in infection group, while the level of CNPase and NF in pup brains at P7 significantly decreased (P<0.05 or P<0.01). Compared with control group, the neonatal rats in infection group had lower birth weight and slower weight gain during the suckling period (P<0.05 or P<0.01), and the completion times of ear opening, eye opening, surface righting, negative geotaxis, acoustic startle and swimming test in infection group were significantly delayed (P<0.05 or P<0.01). Conclussion:Intrauterine infection in pregnant rats can induce cerebral white matter damage and retardation of early growth and neurobehavioral development in neonatal rats.
目的: 探讨宫内感染对新生大鼠出生后早期生长发育和神经行为发育的影响。
方法: 通过将大肠埃希菌注入孕15 d的SD大鼠的子宫颈内建立宫内感染大鼠模型，并观察宫内感染对孕鼠分娩的影响。HE染色法观察新生大鼠脑白质组织病理学变化；免疫组织化学染色和蛋白质印迹法检测新生大鼠脑白质组织胶质细胞原纤维酸性蛋白（GFAP）、2′，3′-环核苷酸磷酸二酯酶（CNPase）、神经丝（NF）表达。随机监测新生大鼠早期生长发育和神经行为功能。
结果: 孕鼠宫内感染后，子宫和胎盘组织白细胞计数升高，提示建模成功，但宫内感染对分娩无显著影响。新生大鼠7日龄时脑白质部位结构稀疏呈筛网状改变，GFAP表达增加（ P＜0.01），而CNPase和NF表达减少（ P＜0.05或 P＜0.01）。与对照组新生大鼠比较，感染组新生大鼠出生体质量轻、体质量增长缓慢（ P＜0.05或 P＜0.01）；耳廓分离、睁眼、平面翻正、负趋地性、听觉惊恐和游泳试验等完成日龄延长（ P＜0.05或 P＜0.01）。
结论: 宫内感染可导致新生大鼠脑白质损伤，并引起新生大鼠早期生长发育及神经行为发育延迟。