Factors influencing villus size in the small intestine of adult rats as revealed by transposition of intestinal segments.
Factors influencing villus size in the small intestine of adult rats as revealed by transposition of intestinal segments.
复制标题
通过肠段转位揭示影响成年大鼠小肠绒毛大小的因素。
DOI：
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发表时间：
1970
影响因子：
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通讯作者：
C. P. Leblond
中科院分区：
文献类型：
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作者：
Gabriel G. Altmann;C. P. Leblond
作为绒毛大小的指标，在大鼠小肠的纵切片中计数每个代表性绒毛切片的上皮细胞数量。绒毛大小沿小肠长度沿着逐渐减小，上十二指肠的绒毛几乎是回肠末端绒毛的3倍。然后检查各种外科手术对绒毛大小的影响。
回肠段插入空肠后，肠绒毛增大至空肠绒毛大小。插入回肠的空肠段，绒毛几乎缩小到回肠绒毛的大小。因此，绒毛大小受环境的影响，也就是说，最有可能是由不同类型的食糜在空肠和回肠。
在插入回肠的十二指肠节段中，绒毛的大小没有减少，并且远端位于回肠的绒毛增大。这个实验和其他实验表明，十二指肠产生的分泌物不仅中和了回肠环境的绒毛减少作用，而且还产生了有效的绒毛扩大作用。幽门分泌物有类似的绒毛扩大的效果。
通过封闭肠段的近端并将其远端与结肠连接，将肠段制成盲囊，以消除食糜的影响。空肠囊和十二指肠下段（不含十二指肠乳头）绒毛缩小，回肠囊增大。因此，在三种类型的囊，有一种趋势，绒毛获得一个中间的大小。
总之，一个中间的绒毛大小，这是假设存在于食糜，无功能的肠，通常会被修改的两种类型的因素：绒毛扩大的因素主要存在于幽门和十二指肠分泌物，和绒毛减少的因素存在于回肠食糜。这些因素之间的相互作用将导致小肠绒毛大小沿着的梯度。
As an index of villus size, the number of epithelial cells per representative villus section was counted in longitudinal sections of the rat small intestine. Villus size was found to decrease gradually along the length of the small intestine, with villi being nearly three times as large in upper duodcnum as in terminal ileum. The influence of various surgical operations on villus size was then examined.
In ileal segments inserted into the jejunum, villi enlarged to the size of local jejunal villi. In jejunal segments inserted into the ileum, villi decreased almost to the size of local ileal villi. Thus, villus size was influenced by the environment, that is, most probably by the different types of chyme in jejunum and ileum.
In duodenal segments inserted into the ileum, villi did not decrease in size, and distally located ileal villi enlarged. This and other experiments indicated that the duodenum produced secretions which not only neutralized the villus-reducing effect of the ileal environment, but also exerted a potent villus-enlarging effect. Pyloric secretions had a similar villus-enlarging effect.
Segments of intestine were made into blind sacs by closing their proximal end and joining their distal end to the colon, so as to remove the influence of the chyme. Villus size decreased in sacs of jejunum and lower duodenum (without the duodenal papilla), but increased in sacs of ileum. Thus in the three types of sacs, there was a tendency for villi to acquire an intermediate size.
In conclusion, an intermediate villus size, which is postulated to exist in chyme-free, non-functional intestine, would normally be modified by two types of factors: villusenlarging factors present mainly in pyloric and duodenal secretions, and villus-reducting factors present in the ileal chyme. Interaction between these factors would result in the gradient of villus size along the small intestine.