[Effect of corticoliberin fragment CRF(4-6) on pain sensitivity in rats].
The effects of corticoliberin fragment CRF(4-6) (Pro-Pro-Ile) on pain sensitivity of rats in "hot plate" test were investigated. Intracerebroventricular administration of tripeptide CRF(4-6) (6, 30, 150 nmol/head) induced dose-dependent antinociception: the latency of paw lick response increased by 7.4 +/- 1.4, 10.1 +/- 1.5 and 16.7 +/- 4.2 s respectively from the basic level of 10.2 +/- 0.9 s. Duration of tripeptide antinociceptive action was 30 min (for 6 nmol) and 60 min (for 30 and 150 nmol). Pretreatment with corticotropin-releasing factor antagonist alpha-helical CRF(9-41) (6.5 nmol/head) 60 minutes before tripeptide administration completely abolished the antinociceptive effects of CRF(4-6) (6 nmol). Therefore corticoliberin receptors seem to be involved in realization of tripeptide influence on pain sensitivity. The data obtained suggest that CRF(4-6) can either directly interact with corticoliberin receptors or modulate activity of CRF-ergic neurons.
Makarenko
E Iu
EIu
Andreeva
L A
LA
Mart'ianov
A A
AA
D000818:Animals; D003346:Corticotropin-Releasing Hormone / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D008297:Male; D010147:Pain Measurement; D017288:Pain Threshold / Q000187:drug effects*; D010446:Peptide Fragments / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains; D018019:Receptors, Corticotropin-Releasing Hormone / Q000187:drug effects / Q000502:physiology
D010446:Peptide Fragments; D018019:Receptors, Corticotropin-Releasing Hormone; C488808:prolyl-prolylisoleucine; D003346:Corticotropin-Releasing Hormone; C045089:corticotropin releasing hormone (9-41)