The role of nitric oxide on the oxytocin induce analgesia in mice

Objective(s): Analgesic effects of oxytocin and it's the other physiological effects were well-known. The aim of present study was determination of nitric oxide role on analgesic effects of oxytocin in mice. Materials and Methods: 216 male Albino mice were divided randomly into two experimental groups, tail flick and formalin test. Each experimental group consists of three main groups including: saline, L-arginine (50 mg/kg) and L-NAME (10 mg/kg) intraperitoneal (IP) injection. 15 min after injection in each of the following groups, the animals in each groups divided to the three subgroups including:  saline (n=12), oxytocin (1 mg/kg) (n=12) and oxytocin (1 mg/kg) + atosiban (1 mg/kg) (n=12) was injected IP and then after 30 min of use the formalin test and tail flick were to evaluate the response to pain. Results: Area under the curve (AUC) in the late phase of the formalin test, in sub-groups oxytocin + saline and L-NAME were significantly decreased compared with saline + saline group (P