Xu R J, Mellor D J, Tungthanathanich P, Birtles M J, Reynolds G W, Simpson H V
Department of Physiology and Anatomy, Massey University, Palmerston North, New Zealand.
J Dev Physiol. 1992 Oct;18(4):161-72.
Growth and morphological changes in the small and the large intestine of piglets were examined during the first three days after birth. There was a 72% increase in small intestinal weight, virtually all of which occurred during the first day and was due primarily to a 115% increase in the weight of the mucosa. Associated with the tissue weight gain there was a 24% increase in small intestinal length, a 15% increase in small intestinal diameter, a 33-90% increase in villus height and a 14-51% increase in villus diameter, during the first day. The cellular population in the small intestinal mucosa, as indicated by its DNA content, increased progressively with age, and at three days had increased by 84-154%. The percentage increase in mucosal DNA content was highest in the duodenum, intermediate in the jejunum and lowest in the ileum. Histological features and tissue protein contents revealed a transient epithelial cellular swelling related to intracellular accumulation of protein on the first day. Protein accumulation was evident in the jejunum and ileum but not in the duodenum. The positions of the nuclei in the epithelial cells suggested that on the first day protein absorption was at a more advanced stage in the jejunum and the proximal ileum than in the distal ileum. Large intestinal weight increased by 33% during the first day and had doubled by the third day, and this weight gain was due to both mucosal and non-mucosal tissue growth. Villus-like structures were observed in the caecum and the proximal colon in piglets at birth and one day after birth but not in piglets three days after birth. It is speculated that such villus-like structures may have a functional significance during the transition to complete dependence on oral nutrition in newborns.
对仔猪出生后前三天小肠和大肠的生长及形态变化进行了检查。小肠重量增加了72%，几乎所有增加都发生在第一天，主要是由于黏膜重量增加了115%。与组织重量增加相关的是，第一天小肠长度增加了24%，小肠直径增加了15%，绒毛高度增加了33% - 90%，绒毛直径增加了14% - 51%。小肠黏膜中的细胞数量，以其DNA含量表示，随年龄逐渐增加，到三天时增加了84% - 154%。黏膜DNA含量增加的百分比在十二指肠最高，空肠次之，回肠最低。组织学特征和组织蛋白含量显示，第一天与细胞内蛋白质积累相关的上皮细胞短暂肿胀。蛋白质积累在空肠和回肠明显，但在十二指肠不明显。上皮细胞核的位置表明，第一天蛋白质吸收在空肠和回肠近端比在回肠远端处于更高级阶段。大肠重量在第一天增加了33%，到第三天增加了一倍，这种重量增加是由于黏膜和非黏膜组织生长。在出生时和出生后一天的仔猪盲肠和近端结肠中观察到绒毛样结构，但在出生三天后的仔猪中未观察到。据推测，这种绒毛样结构在新生儿向完全依赖口服营养过渡期间可能具有功能意义。
