犊牛小肠肌间神经丛NOS阳性神经元的发育学变化

Developmental changes of nitric oxide synthase positive neurons in myenteric plexus of small intestine in calf

用NADPH-黄递酶组织化学方法对1、4和6月龄利杂犊牛小肠肌间神经丛NOS阳性神经元的形态、分布和数量进行了比较研究。结果显示,利杂犊牛小肠肌间神经丛NOS阳性神经元和阳性神经纤维形成清晰的三级网状结构,NOS阳性神经元形态各异,聚集在一起构成大小不等的神经节。小肠各段神经丛中NOS阳性神经元的密度随年龄增长而降低;4月龄到6月龄犊牛空肠肌间神经节的NOS阳性神经元数量变化与十二指肠和回肠相比变化较大;4月龄以空肠的肌间神经丛NOS阳性神经元的核质比(为0.16)最小,回肠与空肠的核质比差异不显著(P>0.05),回肠、空肠与十二指肠的核质比差异显著(P<0.05),6月龄空肠的核质比(为0.25)最大,但小肠各段的核质比相互间差异不显著(P>0.05)。证实,犊牛小肠各段肌间神经丛NOS阳性神经元核质比的发育变化可能与其功能的变化有关。

Using the NADPH-diaphorase histochemistry staining, the morphology, distribution and quantities of the nitric oxide synthase（NOS） positive neurons in myenteric plexus of small intestine were observed in calf of 1-,4- and 6 month-old. The NOS positive neurons and NOS positive nerve fibers in myenteric plexus of calf small intestine formed clearly a three-class reticular formation. The shapes of NOS positive neurons were different, and lots of neurons gathered together, forming some ganglion of different sizes. The density of NOS positive neurons in the plexus of each small intestinal segment decreased while the ages of calf increased. Quantitive variational extent of NOS positive neurons in the myenteric plexus of calf jejunum from 4-month-old to 6-month-old was bigger than that of duodenum and ileum. Ratio between nuclear and somatic area of NOS positive neurons in the myenteric plexus in calf jejunum, 0.16, was least on 4-month-old,which did not differ between jejunum and ileum,but they were significant difference comparable to duodenum. On 6-month-old, the ratio 0.25,was the largest. There was no difference among duodenum,jejunum and ileum each other. In conclusion, developmental changes of the ratio of the NOS positive neurons in the myenteric plexus in calf＇s small intestinal segments may correlate to their functions.