人胎大肠氮能神经元发育的研究

用NADPH-d组织化学法对人胎大肠氮能神经元的发育进行了观察.结果表明第5个月胎龄时,肌间神经节处圆形细胞中部分细胞出现一氧化氮合酶(NOS)阳性反应,并分化成氮能神经细胞.第6个月胎龄时,氮能神经元胞体增大,突起伸长,在肌层、粘膜下层和肠腺基部出现氮能神经纤维分布.第7个月胎龄时,氮能神经元生长发育达到高峰,肌间神经节细胞数目增多,环肌层神经纤维分布密度增加,膨体结构明显.第8-10个月胎龄时,氮能神经元染色强度加深,其胞体分布以肌间神经节最多,粘膜下层和内环肌层较少.氮能神经纤维的分布密度以内环肌层最高,粘膜下层和外纵肌层次之,粘膜层较低.本研究揭示了大肠氮能神经元发育的变化规律.

A study on the development of the nitrergic neurons in the large intestine of human fetus

By using histochemical methed of NADPH-di-aphorse, the development of the nitrergic neurons in the large intestine of human fetus were studied. The results showed: At the fifth month of gestation, weak positive reaction of nitric oxide synthase (NOS) appeared in part of the round cells of intermuscular ganglia. The round cells differentiated into the nitrergic nerve cells. At the sixth month, the bodies of nitrergic neurons were obviously enlarged, the processes of which were lengthened. The nitrergic nerve fibers were seen in the muscle layer, the submucosa and the base of the intestinal gland. The growth and development of nitrergic neurons reached its peak at the seventh month. The number of intermuscular ganglionic cells was increased. The density of nitrergicnerve fibers was increased in the inner circular muscle layer , and have bead-like structures. At the eighth to tenth month, the staining intensity of nitrergic neurons was increased. The myenteric plexus was densely distributed with nitrergic nerve cell bodies, whereas the submucosa and the inner circular muscle layers contained only a few neurons . The nitrergic nerve fibers were observed in all layer of large intestine, the density of the distribution of nitrergic nerve fibers was by far the highest in the inner circular muscle layer, less in the submucosa and outer longitudinal muscle layer, and only a few were found in the mucous layer. To our knowlege, it is the first time that the development of nitrergic neurons in the large intestine of human fetus was demonstrated.