Hyperalgesia induced by morphine on incision pain in rats / 上海第二医科大学学报

ABSTRACT

Objective To investigate the roles of different effective dosages of morphine on incision pain in rats.Methods Clean-degree male SD rats were randomly allocated to three groups(n=11) normal saline group(NS group),low-dose morphine group(LM group,0.6 mg/kg) and high-dose morphine group(HM group,6 mg/kg).After administration of morphine twice at 30 min interval,the incision pain models of rats were prepared according to the Brennan's method.Morphine was administered once again following the operation,while the NS group was administrated isovolumic normal saline.Then the mechanical threshold of rats was detected with von Frey filaments from the pre-operation to the 8th postoperative day,and the hyperalgesia induced by morphine on the praxiology level was explored. ResultsThe values of mechanical threshold postoperation in each group were significantly lower than those of the baseline.The mechanical threshold of HM group was significantly higher than the NS group on the second day postoperation(P