Orphanin FQ/nociceptin-immunoreactive nerve fibers parallel those containing endogenous opioids in rat spinal cord.
Antisera were developed that specifically recognize orphanin FQ/nociceptin, the 17 amino acid peptide reported to be the endogenous ligand for the orphan opioid receptor. Immunocytochemical localizations in rat spinal cord demonstrated that orphanin FQ /nociceptin-immunoreactivity (-ir) was abundant in superficial dorsal horn, lateral spinal nucleus and the region dorsal to the central canal, areas that also exhibit prominent enkephalin-and dynorphin-ir. Orphanin FQ/nociceptin-ir was not affected by dorsal rhizotomy, indicating that in spinal cord the peptide is produced by central rather than primary afferent neurons. thus, the distribution of orphanin FQ/nociceptin-ir appeared in neuronal circuits that parallel those containing enkephalin- and dynorphin-ir, with only modest co-existence of these peptides.
Riedl
M
M
Department of Cell Biology and Neuroanatomy, University of Minnesota, Minneapolis 55455, USA.
Shuster
S
S
Vulchanova
L
L
Wang
J
J
Loh
H H
HH
Elde
R
R
D000595:Amino Acid Sequence; D000818:Animals; D004399:Dynorphins / Q000032:analysis; D004745:Enkephalins / Q000032:analysis; D007150:Immunohistochemistry; D008297:Male; D008969:Molecular Sequence Data; D009294:Narcotics / Q000032:analysis*; D009412:Nerve Fibers / Q000737:chemistry*; D009474:Neurons / Q000737:chemistry; D018847:Opioid Peptides / Q000032:analysis*; D051381:Rats; D017207:Rats, Sprague-Dawley; D011957:Receptors, Opioid / Q000819:agonists*; D013116:Spinal Cord / Q000737:chemistry*; D000097629:Nociceptin
D004399:Dynorphins; D004745:Enkephalins; D009294:Narcotics; D018847:Opioid Peptides; D011957:Receptors, Opioid; D000097629:Nociceptin