豚鼠Oddi括约肌内Cajal样细胞及NOS表达阳性神经元的分布

Distribution of ICC-like cells and NOS positive neurons in the guinea pig sphincter of Oddi

目的研究Cajal样细胞和一氧化氮合酶(nitric oxide synthase,NOS)表达阳性神经元在成年豚鼠Oddi括约肌(sphincter of Oddi,SO)的分布。方法成年豚鼠SO冷冻切片,c-Kit免疫细胞化学和NADPH-黄递酶组织化学双重染色。结果SO横切面环行平滑肌层内可见少量c-Kit阳性细胞,胞体呈梭形,两端伸出细长的突起。纵切面SO的两个壁分别为:外侧壁和十二指肠壁内SO壁,前者与肠壁结构类似,在深肌丛和肌间神经丛周围可见较多的c-Kit阳性细胞;而十二指肠壁内SO壁的肌层内存在大量c-Kit阳性细胞和突起,其形态与肠壁肌层内Cajal细胞相似。NADPH-黄递酶组织化学染色可见NOS表达阳性神经元广泛分布于SO的肌间神经丛和平滑肌内。c-Kit免疫细胞化学和NADPH-黄递酶组织化学双重染色虽未发现二者的共存,但可见c-Kit阳性细胞及突起存在于NOS表达阳性神经元的附近。结论豚鼠SO内存在的Cajal样细胞可能参与SO自主节律性运动的调控,可能是NOS表达阳性神经元对SO运动发挥调节作用的靶细胞。

Objective To study the distribution of ICC-like cells and NOS positive neuron in aduh guinea-pig sphincter of Oddi （SO）. Methods Cryo-sections of SO samples from adult guinea pigs were examined for detection of c-Kit and for NADPH-diaphorase by immunocytochemistry or histochemistry. Results In cross sections, a few c-Kit immunopositive cells were seen in the circular smooth muscle layers of SO. The cells were spindle shape cells with two slender processes. In the longitudinal sections, SO was composed of out wall and intraduodenal wall. The former was similar to intestinal wall and many c-Kit positive cells were seen in the regions of the deep muscular plexus and the myenteric plexus. Plenty of c-Kit positive cells and processes were found in the muscle layers of the intraduodenal wall, like intramuscular interstitial cells of Cajal （ICC-IM） in the intestinal wall. On the other hand, NADPH-d staining showed that a large number of NOS positive nerve fibers widely distributed in the myenteric plexus and smooth muscle layers of SO. Although no NOS reactive neurons were observed in the c-Kit positive cells, their cytoplasmic processes close to the NOS positive neurons were often encountered. Conclusions Our results show that ICC-like cells widely existing in the SO of guinea pigs may be involved in the regulation of the auto-rhythm movement of SO and perhaps are the targets of NOS positive neurons mediating the motility of guinea pig SO.