饥饿对漠斑牙鲆消化道组织结构的影响

Effects of Starvation on Histological Structure of Digestive Tract of Paralichthys lethostigma

应用解剖、常规石蜡切片和显微摄影等技术,观察了漠斑牙鲆消化道的组织结构,对饥饿前后漠斑牙鲆的食道、胃和肠道纹状缘高度、柱状细胞高、壁厚、肌肉层厚以及食道、肠道杯状细胞大小进行了测量。结果表明,漠斑牙鲆消化道由内向外分为粘膜层、粘膜下层、肌肉层和浆膜层。食道粘膜上皮为复层上皮,胃本体和肠道粘膜上皮为单层柱状上皮,直肠粘膜上皮为假复层纤毛柱状上皮。除胃本体外,从食道到直肠粘膜上皮中均有杯状细胞分布,但其数量呈减少趋势。粘膜下层主要由疏松结缔组织构成。食道肌肉层为内纵外环的横纹肌,胃本体、肠道及直肠肌肉层为内环外纵的平滑肌。漠斑牙鲆饥饿10 d后各段消化道的褶皱高度降低,纹状缘边界不光滑,甚至局部断裂,肌层和粘膜下层连接疏松。消化道显微结构的测量结果显示,饥饿后粘膜上皮中的杯状细胞显著变小,胃、肠、直肠的柱状上皮细胞高度显著下降,肠前段和中段肌肉层厚和壁厚度呈显著下降。

The techniques of anatomy, paraffin section and photomicrography were used in this paper. Histological structure of the digestive tract of Paralichthys lethostigma and histological changes including thickness of striated border, height of columnar cell, thickness of wall and muscle layer in digestive tract as well as the size of mucous cell in esophagus and intestine following starvation for 10 days were assessed by light microscopy. The results show that the digestive tract of Paralichthys lethostigma consisted of mucosa, submucosa, muscles and serosa layer. The mucosal epithelium of the esophagus was stratified squamous epithelium, while epithelium in stomach and intestine’s was simple columnar epithelium, and it was pseudostratified ciliated columnar epithelium in rectum. Goblet cells existed between the epithelial cells in digestive tract except stomach. Submucosa layers were loose connective tissue. The muscle of esophagus was striated muscle arranged in the inner longitudinal and outer circular. However, in other segments of digestive tract, the muscle was composed of smooth muscle cells and the cells arrangement patterns were opposite to that of esophagus musclar layer. Starvation for 10 days resulted in the decrease of height of mucosa rugae, disruption and exfoliation of the striated border, and the connection between the size of goblet cells significantly reduced. The height of columnar cells in stomach, intestine and rectum, as well as the thickness of muscle layer and the wall of foregut and midgut significantly decreased. This study provided scientific data for understanding Paralichthys lethostigma to the starvation tolerance and artificial culture of the fish.