흰쥐에서 척수신경 등쪽뿌리 절단후 척수 등쪽뿔의 substance P 및 calcitoningene-related peptide 함유 신경섬유에 대한 면역조직화학적 연구

Abstract

Calcitonin gene-related peptide (CGRP) has same distribution pattern to those of substance P in spinal dorsal horn and coexist in perikarya of the spinal dotsal root ganglia and several studies have concluded that there is a synergistic interaction with substance P although the nature of interaction is still in dispute. It was proved light microscopically that the origin of CGRP in the spinal dorsal horn is entirely from primary afferent dorsal root gang1ion cell. Subsance P considered to exist in both popriospinal and pylmary afferent fibers. In the present study, the origin of CGRP and substance P immunoveactivity in the dorsal horn was investigated electron microscopically after dorsal rhizotomy to eliminate primary afferent input . Also the area and gray level of the CGRP and substance P immunoreactivity of dorsal rhizotomized dorsal horn was determined by area densitometry of image analyzer. The results are summerized as follows. 1. Area of the GGRP-immunolabelled dorsal horn has disappeared entirely after bilateral dorsal rhizotomy. 2. Area of the substance P-immunolabelled ayes was decreased after dorsal rhino homy. Average levels of L6-S2 segments were 59.5% to 68.2% of control level. Gray level of the substance P immunolabelled area was also decreased. Average levels of 6-S2 segments weve 59.5% to 68.2% of control level. 3. CGRP immunolabelled profiles were found in axons and axon terminals while substance P-immunolabelled structures were found in dendrites as well as in axons and their terminals. 4. CGRP immunolabelled profiles observed in electron microscopy were disappeared almost entirely after multiple bilateral dorsal rhizotomy while substance P-immunolabelled profiles were still found in dendrites, axons, and in axon terminals. In this study the kyopothesis that the CGRP immunoyeactivlty in the dorsal horn of rat spinal cord is a primary afferentl fibers were confirmed in electron microscopic level. Also substance P immnoreactivity in the dorsal horn after multiple bilateral dorsal rhizotomy was determined quantitatively.