| Sex differences related with pain have been studied and evidences suggesting influence of sex steroid hormones on the thresholds of pain. Experimental nociception has been test using formalin as a model of nociceptive stimulus. Association of stress, pain and metabolic and hormonal changes has not been explored. The aim of this study was to compare metabolic and hormonal changes between male rats and female rats in proestrus and estrus cycle after painful stimulus by formalin into the masseter muscle. Male and female Wistar rats (200-250 g b.w.) were submitted to an injection of formalin (F, 1.5%) or saline (S, 9.9%) into the masseter muscle and after 0 (N, control group without injection), 5, 15, 30 or 60 minutes they were decapitate and blood was... |
