Analgesic actions of corticotropin-releasing factor (CRF) on somatic pain sensitivity: involvement of glucocorticoid and CRF-2 receptors.
The aim of the present work was to study the involvement of glucocorticoid receptors and corticotropin-releasing factor type 2 receptors (CRF-2 receptors) in mediating the analgesic effects of CRF on somatic pain sensitivity. The involvement of glucocorticoid and CRF-2 receptors in the development of analgesia evoked by systemic administration of CRF was studied by blockade of these receptors by their specific antagonists RU 38486 and astressin 2-B, respectively, in anesthetized rats. Pain sensitivity was tested before and 30 min after administration of CRF in terms of the threshold of the pain reaction induced by stimulation of the rat's tail with an electric current. Blockade of glucocorticoid receptors induced partial suppression of the analgesic action of CRF, while blockade of CRF-2 receptors produced complete suppression of the analgesic effect. These results provide evidence that glucocorticoid and CRF-2 receptors are involved in mediating the analgesic effects of CRF.
Yarushkina
N I
NI
Experimental Endocrinology Laboratory, I. P. Pavlov Institute of Physiology, Russian Academy of Sciences, 6 Makarov Bank, 199034, St. Petersburg, Russia.
Bagaeva
T R
TR
Filaretova
L P
LP
D000700:Analgesics / Q000494:pharmacology*; D000818:Animals; D003346:Corticotropin-Releasing Hormone / Q000494:pharmacology*; D006727:Hormone Antagonists / Q000494:pharmacology; D008297:Male; D015735:Mifepristone / Q000494:pharmacology; D010146:Pain / Q000188:drug therapy / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D018019:Receptors, Corticotropin-Releasing Hormone / Q000819:agonists / Q000037:antagonists & inhibitors / Q000378:metabolism*; D011965:Receptors, Glucocorticoid / Q000819:agonists / Q000037:antagonists & inhibitors / Q000378:metabolism*; D013997:Time Factors
D000700:Analgesics; C101531:CRF receptor type 2; D006727:Hormone Antagonists; D018019:Receptors, Corticotropin-Releasing Hormone; D011965:Receptors, Glucocorticoid; D015735:Mifepristone; D003346:Corticotropin-Releasing Hormone