不同张力扩张子宫颈诱导大鼠延髓内脏带c-Fos及神经型一氧化氮合酶的表达变化

Expression changes of c-Fos and neuronal nitric oxide synthase in medullary visceral zone induced by varied distention of uterine cervicx

目的观察不同张力扩张子宫颈(UCD)诱导大鼠延髓内脏带神经元c-Fos和神经型一氧化氮合酶(n NOS)的表达变化,探讨UCD疼痛在延髓水平的传导机制。方法成年雌性SD大鼠随机分为对照组(UCD 0g)、宫颈扩张50g张力组(UCD 50g)和宫颈扩张100g张力组(UCD 100g)。UCD组大鼠实施50g及100g张力扩张刺激,UCD刺激后2h,取延髓组织采用还原型辅酶Ⅱ(NADPH)组织化学和c-Fos免疫组织化学双重染色法观察c-Fos、n NOS和c-Fos/n NOS阳性神经元的分布,Western blotting和Real-time PCR法分别检测c-Fos及n NOS蛋白和mRNA水平。结果 c-Fos免疫阳性神经元的细胞核为棕黄色,呈圆形或卵圆形,胞质不着色。n NOS阳性神经元的胞体和突起呈蓝色,胞核不着色,呈空泡状。c-Fos/n NOS双标神经元的胞体和树突染成蓝色,细胞核呈棕黄色,这些神经元主要分布于延髓孤束核(NTS)和外侧网状核(LRN)内。与UCD 0g组相比,UCD 50g组和UCD 100g组大鼠NTS和LRN内c-Fos、n NOS以及c-Fos/n NOS阳性神经元数量明显增加,染色明显加深,c-Fos、n NOS蛋白及mRNA水平均明显升高(P<0.01)。结论大鼠急性UCD可导致NTS和LRN神经元c-Fos及n NOS张力依赖性表达增加,NTS和LRN内的n NOS阳性神经元可能参与UCD疼痛在延髓水平的传导。

Objective To investigate the expression changes of neuronal nitric oxide synthase（ n NOS） and c-Fos in the rat medullary visceral zone with different uterine cervical distension（ UCD）,of which the transferring mechanism in the medulla oblongata is still unclear. Methods Adult female Sprague-Dawley rats were randomly divided into the control group（ UCD 0g）,50 g tension group（ UCD 50g） and 100 g tension group（ UCD 100g）. The UCD model was established through distension forces generated by hanging different standard weights（ 50 g,100g） at the end of metal crooks. The distribution of n NOS,c-Fos and c-Fos / n NOS positive neurons was observed 2 hours after UCD by NADPH histochemistry and c-Fos immunohistochemistry. The protein expression of n NOS and c-Fos in the medulla oblongata was detected by Western blotting. The mRNA expression of n NOS and c-Fos in the medulla oblongata was detected by Real-time PCR.Results c-Fos immunoreactive neurons in nucleus were brown,round or oval,while the cytoplasm was unstained. Thecell bodies and processes of n NOS positive neurons were blue,and the nuclei were not stained in the form of a bubble.c-Fos / n NOS double labeled cell bodies and dendrites of neurons stained blue,and nucleus showed brown yellow. These neurons were mainly distributed in the nucleus of the solitary tract nucleus（ NTS） and the lateral reticular nucleus（ LRN）.Compared with UCD 0 g group,the number of n NOS,c-Fos and c-Fos / n NOS positive neurons in the NTS and LRN of UCD50 g group and UCD 100 g group were significantly increased,and the dyeing significantly deepened. The protein and mRNA levels of c-Fos,n NOS in UCD 100 g group were higher than that of UCD 50 g group（ P〈 0. 05）. And both of the two groups were significantly elevated（ P〈 0. 01） as compared with UCD 0 g group. Conclusion Acute uterine cervical dilatation in rats can lead to increased expression of c-Fos and n NOS in NTS and LRN of the medulla oblongata,n NOS positive neurons in NTS and LRN may be involved in the conduction of the UCD pain in the medulla oblongata.