DARU Journal of Pharmaceutical Sciences133Sex affects the feeling of pain in the mice, possible involvement of nitric oxide116119"Zahra Fatehi-HassanabadMostafa JafarzadehMohammad FatehiMohammad Taghi Razavi-Tossi"20151006It has been shown that nitric oxide is a mediator with a major role in pain signaling at the level of dorsal root ganglion neurons of the spinal cord. The main objective of the present study was to elucidate the influence of sex on the effects of nitric oxide on pain mediation in mice. Painful stimuli such as heat induced by light beam focused on tail and hot plate chamber were applied. Animals were injected with either morphine (0.5, 5 and 50 mg/100g body weight) or L-NAME (0.1, 0.5 and 1 mg/100g body weight) intraperitonealy. Changes in tail flick latency and responses to the hot plate chamber were measured in different groups of mice. The tail flick latency was increased significantly in both male and female animals treated with morphine (control male (sec): 2.45 ± 0.16, male which received morphine 50 mg/100g body weight: 13.5 ± 0.6, control female: 3.4 ± 0.3, female which received morphine 50 mg/100g body weight: 13.8 ± 0.6; Phttps://daru.tums.ac.ir/index.php/daru/article/view/244https://daru.tums.ac.ir/index.php/daru/article/download/244/244