Effect of morphine on neurological and histological outcomes, brain water content, vestibulomotor function, brain edema in traumatic brain injury

Background and Aim : TBI (traumatic brain injury) is one of the main causes of mortality and disability among young people. TBI has two events: primary injury and secondary injury. The secondary injury is the main cause of morbidity and disability after TBI. In past researchers had found that if we inject morphine and opioid-like to the body it has an analgesic effect. That shows we have opioid receptors naturally in the body. Endogenous opioids may have an important role in the pathophysiology of TBI because they release in brain injury in some regions that receive damage. Recently researches show that injection of morphine after trauma (within an hour) may decrease secondary injury. Morphine is an opioid that can decrease pain in moderate and severe pain. So in this research we are looking for these questions that: firstly, can morphine be effective in procedure of brain trauma. secondly, which dose of morphine is more effective in treatment of TBI.Methods : For this study male wistar rats were used.The rats divided into 8 groups in this experiment: intact, sham, TBI, saline, 1 mg/kg morphine, 5 mg/kg morphine, 10 mg/kg morphine, 5 mg/kg morphine + Naloxone. We measured neurological outcomes, vestibulomotor function, behavioral tests, brain edema, and histopathological outcomes. The result showed significant increasing in neurological scores and behavioral scores within 4 times (day 0, 1, 2, 3) in 5 mg/kg morphine.Results : There was significant difference between intact or sham groups and TBI or saline. That shows secondary injuries of TBI have some significant effects. There was some improvement in treatment with 1 mg/kg and 5 mg/kg morphine, but there was no significant difference between in 10 mg/kg morphine or 5 mg/kg morphine + naloxone and TBI or saline.Conclusion : This study investigates the opioid receptor s roles in the secondary injury of traumatic brain injury. Evidence of this study confirms that ORs may have neuroprotective roles in TBI. In this test, some parameters were measured to check drug effects. In addition to that, another important target was finding the effective dose of the drug in TBI treatment. The result conduct that 5mg/kg morphine is the most effective dose to suppress effect of TBI among the experimental groups. The result of this study shows this drug can reduce secondary injury like brain edema, which is a similar symptom to strokes and ischemia.

کلیدواژه ها:

traumatic brain injury ، opioid receptor ، morphine