[Mechanisms of corticotropin-releasing factor-induced analgesic effect in conscious rats].
The aim of study was to investigate a contribution of hypothalamic-pituitary-adrenocortical (HPA) axis and opioid system in corticotrophin-releasing factor (CRF)-induced analgesic effect in conscious rats during thermal stimulus. The contribution of HPA axis in CRF-induced analgesia was studied with two approaches: 1) pharmacological suppression of HPA axis activity induced by cortisol administration in pharmacological dose one week before experiment; 2) occupation of glucocorticoid receptors by its antagonist RU 38486. The opioid antagonist naltrexone was used to examine the involvement of opioid system in CRF-induced analgesia. Blockade of opioid receptors by its antagonist completely eliminated CRF-induced analgesic effect. Pharmacological suppression of HPA axis resulted in a decrease of CRF-induced analgesic effect, blockade of glucocorticoids receptors by RU-38486 potentiated CRF-induced analgesic effect. The data obtained suggest that CRF-induced analgesic effect is mediated by opioids. The effect ofopioids upon pain sensitivity may be modulated by glucocorticoid hormones.
Iarushkina
N I
NI
Bagaeva
T R
TR
D018712:Analgesics, Non-Narcotic / Q000494:pharmacology*; D000818:Animals; D000893:Anti-Inflammatory Agents / Q000494:pharmacology; D003346:Corticotropin-Releasing Hormone / Q000494:pharmacology*; D006727:Hormone Antagonists / Q000494:pharmacology; D006728:Hormones / Q000494:pharmacology; D006854:Hydrocortisone / Q000494:pharmacology; D007030:Hypothalamo-Hypophyseal System / Q000378:metabolism* / Q000503:physiopathology; D008297:Male; D015735:Mifepristone / Q000494:pharmacology; D009271:Naltrexone / Q000494:pharmacology; D009292:Narcotic Antagonists / Q000494:pharmacology; D010146:Pain / Q000378:metabolism* / Q000503:physiopathology; D010913:Pituitary-Adrenal System / Q000378:metabolism* / Q000503:physiopathology; D051381:Rats; D017207:Rats, Sprague-Dawley; D011957:Receptors, Opioid / Q000378:metabolism
D018712:Analgesics, Non-Narcotic; D000893:Anti-Inflammatory Agents; D006727:Hormone Antagonists; D006728:Hormones; D009292:Narcotic Antagonists; D011957:Receptors, Opioid; D015735:Mifepristone; D009271:Naltrexone; D003346:Corticotropin-Releasing Hormone; D006854:Hydrocortisone