بررسى تفاوت اثر ضد دردى مرفين و تحمل به مرفين بين موش كوچك نر و ماده

The difference of analgesic effect of morphine and tolerance to morphine between male and female mice

The sex -dependent changes of behavioral responses of humans and animals have been widely investigated. There are also controversial reports regarding the role of sex hormones in pain and analgesic effects of morphine. In the present study morphine tolerance and its analgesic effects in male and female mice was investigated. Twenty mice were divided into male and female groups. The hot plate test was carried out as a base record. Then the animals received 10 mg/kg (S.C.) morphine and antinociceptive effect was evaluated every 15 min. Morphine tolerance was induced by injection of 30 mg/kg morphine. 3 times a day. during 3 consecutive days. Finally. the analgesic effect of morphine was evaluated after injection of morphine (10 mg/kg).Before morphine tolerance. the reaction times after injection of morphine (10mg/kg) were longer than base times in both female and male groups while after tolerance induction. there was no difference between base times and reaction times. All reaction times after injection of morphine in male group were more than female group. There was no significant difference in reaction times in both male and female tolerated animals after injection of 10 mg/kg of morphine.