Evidence that N-terminal fragments of nociceptin modulate nociceptin-induced scratching, biting and licking in mice.
The intrathecal (i.t.) injection of 3.0 fmol nociceptin (orphanin FQ) elicited scratching, biting and licking responses in mice. N-terminal fragments of nociceptin, nociceptin (1-7), nociceptin (1-9) and nociceptin (1-13), induced no characteristic behavioral response. When these N-terminal fragments of nociceptin were injected simultaneously with nociceptin, the behavioral response induced by nociceptin was reduced dose-dependently. Nociceptin (1-13) was much more potent than nociceptin (1-7) and nociceptin (1-9) and antagonized nociceptin-induced response at equimolar doses. No significant effects of the N-terminal fragments were observed against the scratching, biting and licking response elicited by i.t. administration of substance P or N-methyl-D-aspartate. These results suggest that N-terminal fragments formed endogenously in the spinal cord may have an antagonistic effect on nociceptin-induced behavioral responses.
Sakurada
T
T
Department of Biochemistry, Daiichi College of Pharmaceutical Sciences, Fukuoka, Japan. tsukasa@daiichi-cps.ac.jp
Sakurada
S
S
Katsuyama
S
S
Hayashi
T
T
Sakurada
C
C
Tan-No
K
K
Johansson
H
H
Sandin
J
J
Terenius
L
L
D000818:Animals; D001733:Bites and Stings / Q000139:chemically induced* / Q000503:physiopathology; D006120:Grooming / Q000187:drug effects* / Q000502:physiology; D008297:Male; D051379:Mice; D009619:Nociceptors / Q000187:drug effects / Q000502:physiology; D018847:Opioid Peptides / Q000737:chemistry / Q000494:pharmacology* / Q000502:physiology; D010446:Peptide Fragments / Q000494:pharmacology*; D011537:Pruritus / Q000139:chemically induced* / Q000503:physiopathology; D013116:Spinal Cord / Q000187:drug effects / Q000502:physiology; D014665:Vasodilator Agents / Q000737:chemistry / Q000494:pharmacology; D000097629:Nociceptin
D018847:Opioid Peptides; D010446:Peptide Fragments; D014665:Vasodilator Agents; D000097629:Nociceptin