Morphological studies on the development of the prenatal and postnatal rat stomach 2. Transmission electron microscopical observations

랫드의 출생전·후의 위조직 발달에 관한 형태학적 연구 2. 투과전자현미경적 관찰

The present study was designed to investigate the morphological developments of the stomach in the prenatal and postnatal rats. The gastric fundus of 16- to 22-day-old fetuses, neonates, 7-day-old, 14-day-old, 21-day-old, and adult rats were observed by transmission electron microscopy. 1. In the 19-day-old fetuses, the gastric pits and the parietal cells were the primitive state, but the parietal cells contained numerous microvilli and mitochondria. 2. In the 20-day-old fetuses, the intracellular canaliculus appeared in the parietal cells, and glycogen granules were localized mainly in the basal part of the epithelial cells and parietal cells. 3. In the 20-day-old fetuses, the mucous granules and zonular occludens appeared in the gastric glandular cells adjacent to the parietal cells. 4. In the 21-day-old fetuses, the chief cells were identified in the lamina propria and these cells contained granular endoplasmic reticulum and zymogen granules. 5. In the 20- to 22-day-old fetuses, the definitive parietal cells were firstly appeared in pairs or groups within the lamina propria. These cells tended to be placed near the basement membrane and blood capillary, and frequently tended to be extruded into lumen of gland. 6. The endocrine cells were appeared at the basal areas of the gastric gland after the 14-day-old.