Changes of spinal substance P, calcitonin gene-related peptide, somatostatin, Met-enkephalin and neurotensin in rats in response to formalin-induced pain.
Changes of substance P (SP)-, calcitonin gene-related peptide (CGRP)-, somatostatin (SS)-, Met-enkephalin (Met-Enk)- and neurotensin (NT)- immunoreactive materials on two sides of the lumbar dorsal horn were inspected microscopically and quantified with a computer-assisted image processing system in rats with intact or totally transected spinal cord 2 h after injection of 0.2 ml of 0.5% formalin into the right hindpaw subcutaneously. The results showed that the SP-like immunoreactivity (SP-LI), CGRP-LI, SS-LI, Met-Enk-LI, and NT-LI were significantly higher in fibers and terminals in superficial laminae of the dorsal horn ipsilateral to the formalin injection in both of the experimental groups. It is supposed that the increased contents of these peptides reflect an increased biosynthesis, transport, and release of these peptides in primary afferents and spinal intrinsic neurons in response to the long-lasting inflow of noxious messages, and that these changes seem to be produced even in the condition when the supraspinal effects have been excluded.
Zhang
R X
RX
Department of Neurobiology, Shanxi Medical College, Taiyuan, China.
Mi
Z P
ZP
Qiao
J T
JT
D000818:Animals; D015740:Calcitonin Gene-Related Peptide / Q000378:metabolism; D004744:Enkephalin, Methionine / Q000378:metabolism; D005260:Female; D005557:Formaldehyde; D007091:Image Processing, Computer-Assisted; D008297:Male; D008854:Microscopy, Electron; D009479:Neuropeptides / Q000378:metabolism*; D009496:Neurotensin / Q000378:metabolism; D010146:Pain / Q000139:chemically induced / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013004:Somatostatin / Q000378:metabolism; D013116:Spinal Cord / Q000378:metabolism*; D013373:Substance P / Q000378:metabolism
D009479:Neuropeptides; D005557:Formaldehyde; D013373:Substance P; D009496:Neurotensin; D013004:Somatostatin; D004744:Enkephalin, Methionine; D015740:Calcitonin Gene-Related Peptide