Intrathecal neuromedin C enhances mechanical nociception: possible involvement of NMDA receptors.
Intrathecal administration of neuromedin C (3, 10 nmol/rat) significantly decreased the nociceptive threshold of rats in the paw-pressure test. This effect was abolished by co-administration of [Leu13 psi(CH2NH)-Leu14]bombesin (10 nmol/rat), a bombesin receptor antagonist. Co-administration of 2-amino-5-phosphonovaleric acid (APV) at a dose (10 nmol/rat) which did not affect the nociceptive threshold by itself significantly inhibited the effect of neuromedin C. 6-Cyano-7-nitroquinoxaline-2,3-dione (CNQX) (10 nmol/rat) did not significantly inhibit the neuromedin C-induced hyperalgesia. These results indicate that neuromedin C could modulate mechanical nociception through bombesin receptors at the spinal level, where glutamate is involved through NMDA receptors.
Onogi
T
T
Department of Pharmacology, Faculty of Pharmaceutical Sciences, Kyoto University, Japan.
Kagawa
M
M
Minami
M
M
Kuraishi
Y
Y
Satoh
M
M
D015763:2-Amino-5-phosphonovalerate / Q000008:administration & dosage / Q000494:pharmacology; D018750:6-Cyano-7-nitroquinoxaline-2,3-dione / Q000008:administration & dosage / Q000494:pharmacology; D000595:Amino Acid Sequence; D000818:Animals; D001839:Bombesin / Q000008:administration & dosage / Q000031:analogs & derivatives / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D018698:Glutamic Acid / Q000378:metabolism; D006614:Hindlimb; D006930:Hyperalgesia / Q000139:chemically induced; D007278:Injections, Spinal; D008297:Male; D008969:Molecular Sequence Data; D010147:Pain Measurement; D017288:Pain Threshold / Q000187:drug effects*; D010446:Peptide Fragments / Q000008:administration & dosage / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D018004:Receptors, Bombesin / Q000037:antagonists & inhibitors / Q000187:drug effects / Q000378:metabolism; D016194:Receptors, N-Methyl-D-Aspartate / Q000187:drug effects / Q000378:metabolism
D010446:Peptide Fragments; D018004:Receptors, Bombesin; D016194:Receptors, N-Methyl-D-Aspartate; C057644:bombesin, Leu(13)-psi-CH2NH-Leu(14)-; D018698:Glutamic Acid; D018750:6-Cyano-7-nitroquinoxaline-2,3-dione; D015763:2-Amino-5-phosphonovalerate; C040794:neuromedin C; D001839:Bombesin