TY - JOUR T1 - Hypothalamus Pituitary Adrenal axis and stimulatory G proteins signaling role in nociceptive changes induced by forced swim stress TT - JF - Physiol-Pharmacol JO - Physiol-Pharmacol VL - 10 IS - 4 UR - http://ppj.phypha.ir/article-1-288-en.html Y1 - 2007 SP - 291 EP - 302 KW - Forced swim stress KW - Analgesia KW - Hyperalgesia KW - HPA KW - Oseltamivir. N2 - Introduction: Different mechanisms are involved in stress induced analgesia (SIA) and hyperalgesia (SIH). Repeated stress induces development of tolerance to SIA. The role of HPA axis and Gs signaling pathway in these effects are investigated in the current study. Methods: Forced swim stress (5 min/day) in water (20±1 ºC) was employed to adult male Wistar rats (200-250 g). The nociceptive threshold was assessed using tail flick test. Adrenalectomized (ADX) rats were also subjected to stress tests. Oseltamivir was used to block Gs signaling pathway. Results: Stress produced analgesia for 1 h (p M3 ER -