Localization of substance P and enkephalin by immunohistochemistry in the spinal cord of human fetus.
The peroxidase-antiperoxidase method was used to study the distribution of substance P and enkephalin during development of the spinal cords of human fetuses. Thirty-seven cases were collected, ranging from 5- to 40-weeks-old (fetal ages). Both types of transmitters were present initially around the fifth week in the mantle layer of the base of the dorsal horn, around the tenth week at the anterior gray and the intermediate gray and around the sixth week at the marginal layer at the base of the ventrolateral funiculus. Substance P- and enkephalin-positive sites at the marginal layers at the base of the dorsolateral funiculus were evident in the same area at 5-6 weeks. The positive fibers in the dorsal horn were initially located in the superficial layers. By the eleventh week, the positive sites spread to other surface layers at the lateral sides of the dorsal horns bilaterally at all spinal levels above the sacral. In the sacral levels adjacent to the conus medullaris, the spreading to surface layers was not apparent bilaterally until the seventeenth week. By weeks 18-26 the positive sites penetrated deeper in the dorsal horn and by week 27 assumed the adult path. The enkephalin cell bodies were present in the Rexed layers I and II of the dorsal horn and the substance P-positive sites were apparent in the dorsal ganglia of the 28-40-week-old fetuses.
Luo
C B
CB
Department of Anatomy, Jinan University, Guangzhou, China.
Zheng
D R
DR
Guan
Y L
YL
Yew
D T
DT
D004745:Enkephalins / Q000378:metabolism*; D005333:Fetus / Q000378:metabolism*; D005865:Gestational Age; D006801:Humans; D007150:Immunohistochemistry; D013116:Spinal Cord / Q000166:cytology / Q000196:embryology / Q000378:metabolism*; D013373:Substance P / Q000378:metabolism*
D004745:Enkephalins; D013373:Substance P