The Morphometric and Ultrastructural Study of Enteric Nervous System in Adult and Aged Rat Small Intestine

Park, Seung Hwa; Cho, Ik Hyun; Lee, Jong Eun; Lee, Won Taek; Park, Kyung Ah

Abstract

This study was performed to investigate the morphometric and ultrastructural change in the adult and aged rat small intestine. The myenteric and submucous plexuses were stained by NADH-TR in the ileum of adult Sprague-Dawley rats (3 mo., 300~350 gm) and aged rats (24 mo., 500~550 gm). The neurons of myenteric and sumucous plexuses were divided into 3 groups depending on their cell body morphology. Type 1 cells were polygonal or round with abundant cytoplasm. Type 2 cells were spindle shaped and type 3 cells were small and round with scanty cytoplasm. The nerve cell numbers and sizes were measured using an image analyzer (VIDAS, Carl Zeiss, Co., Ltd.). Ultrastructural changes were observed by JEM-1200 EXII (JEOL Co., Ltd.) electron microscope. The result obtained are as followed: 1. In adult rats, majority of neuron population were type 3 and neuron density (total numbers/1 mm2) was more higher in submucous plexus than in the myenteric plexus. 2. Statistically significant loss of type 1 and type 2 neurons were in myenteric and submucous plexus of aged rat small intestine. 3. All types of neuron sizes were increased in aged myenteric and submucous plexuses. 4. Lipofusin granules were prominent in the cytoplasm of aged rat. Cell organelles were not shown degenerative change. These results suggest that type 1 and type 2 nerve cells which is originated from autonomic nerves were lost in aged rat small intestine. Ultrastructurally lipofusin granules were prominent in the cytoplasm of aged rat and the cell organelles were not degenerated.