Shen Ying, Yu Hui-Min, Yuan Tian-Ming, Gu Wei-Zhong, Wu Yi-Dong
Department of Neonatology, Children's Hospital, Zhejiang University School of Medicine, Hangzhou, PR China.
J Perinat Med. 2007;35(3):203-9. doi: 10.1515/JPM.2007.058.
In order to investigate the neuropathological effect on the developing rat brain after intrauterine infection, 2', 3'-cyclic nucleotide 3'-phosphodiesterase (CNPase) and inducible nitric oxide synthase (iNOS) were evaluated.
Escherichia coli (E. coli) was inoculated into the uterine cervix of the time-pregnant rats and controls were injected with normal saline. Immunohistochemical staining for CNPase was performed to assess oligodendrocyte injury in pup brains at postnatal day 1, 3 and 7 (P1, P3, and P7). Immunohistochemistry was used to evaluate iNOS expression and quantitative reverse transcriptase PCR to analyze iNOS mRNA expression in pup brains at P1, P3 and P7. Nitrate reductase method was used for detection of nitric oxide (NO) concentration in pup brains at P1, P3 and P7.
The immunohistochemical staining for CNPase in the E. coli-treated group showed a decrease compared with the control in periventricular white matter at P7. Obvious immunohistochemical staining of iNOS was observed in periventricular white matter of the E. coli-treated pup brains at P1. The expression of iNOS mRNA in the E. coli-treated pup brains increased at P1 and P3, but there was no significant difference at P7 compared with controls. Similarly, the NO concentration increased in the E. coli-treated pup brains at P1 and P3, and no significant difference was found at P7 compared with controls.
The alteration of CNPase expression indicates that intrauterine infection could cause oligodendrocyte injury in the developing brain. Moreover, the increased expression of iNOS followed by the increasing NO concentration after intrauterine infection suggests that iNOS might be a key mediator between the intrauterine infection and oligodendrocyte injury in the developing brain.
为了研究宫内感染后对发育中大鼠脑的神经病理学影响，对2',3'-环核苷酸3'-磷酸二酯酶（CNPase）和诱导型一氧化氮合酶（iNOS）进行了评估。
将大肠杆菌接种到孕鼠子宫颈，对照组注射生理盐水。在出生后第1天、3天和7天（P1、P3和P7）对幼鼠脑进行CNPase免疫组织化学染色，以评估少突胶质细胞损伤。采用免疫组织化学评估iNOS表达，并通过定量逆转录聚合酶链反应分析P1、P3和P7时幼鼠脑中iNOS mRNA表达。采用硝酸还原酶法检测P1、P3和P7时幼鼠脑中一氧化氮（NO）浓度。
与对照组相比，大肠杆菌处理组在P7时脑室周围白质中CNPase免疫组织化学染色减少。在P1时，大肠杆菌处理的幼鼠脑室周围白质中观察到明显的iNOS免疫组织化学染色。大肠杆菌处理的幼鼠脑在P1和P3时iNOS mRNA表达增加，但与对照组相比，P7时无显著差异。同样，大肠杆菌处理的幼鼠脑在P1和P3时NO浓度增加，与对照组相比P7时无显著差异。
CNPase表达的改变表明宫内感染可导致发育中脑的少突胶质细胞损伤。此外，宫内感染后iNOS表达增加，随后NO浓度升高，提示iNOS可能是宫内感染与发育中脑少突胶质细胞损伤之间的关键介质。
