大鼠脑发育过程中神经型一氧化氮合酶的表达变化

Changes of the expressions of nNOS during the development of brain in rats

目的用免疫组化方法探讨神经型一氧化氮合酶在大鼠脑发育过程中的表达变化。方法分别随机选取E12、E15、E18、P0、P5及P10期的SD大鼠,应用免疫组化方法,检测大脑皮层、纹状体及海马nNOS阳性细胞的密度。结果E12、E15及E18期大鼠脑组织未见nNOS阳性细胞;大脑皮层及纹状体区P0、P5及P10期均可见nNOS阳性细胞。nNOS阳性细胞密度,在P0、P5及P10期逐渐降低,两两比较,有显著性差异(P<0.05)。P0期海马偶见nNOS阳性细胞,P5期和P10期均可见较多nNOS阳性细胞,但nNOS阳性细胞密度P5和P10期之间无统计学差异(P>0.05)。结论胚胎期大鼠脑内nNOS染色呈阴性反应;生后大脑皮层及纹状体nNOS阳性细胞密度逐渐减小,海马nNOS阳性细胞密度则有所增加。

Objective To observe the expression of neuronal nitric oxide synthase （nNOS） during the growth of brain in rats with immunohistochemical method. Methods Fetal and newborn rats were randomly selected, and divided into 6 groups according to developmental stages of E12, E15, E18, P0, P5 and P10. The sections were stained by nNOS immunohistochemical staining. The density of nNOS immunoreactive cells was collected and measured by image gathering and analysis software in the sections of cerebral cortex, striatum and hippocampus. Results nNOS immunoreactive cells were not found at telencephalon in fetal rats. In newborn rats, the density of nNOS immunoreactive cells was the highest at P0 in the cerebral cortex and striatum, and reduced sequentially at P5 and P10. In the hippocampus, the number of nNOS immunoreative cells at P5 and P10 was obviously larger than that at P0. There was no significant difference between P5 and P10. Conclusion nNOS immunohistochemical staining is negative at telencephalon in fetal rats. With the development of the cortex and striatum, the expression of nNOS declines in newborn rats. However, it increases in the hippocampus during the growth.