Effect Of Estrogen On Cerebral Edema And Expression Of Bcl-2 And Bax Of Impaired Brain Tissue After Traumatic Brain Injury In Rats

Objective:To investigate whether the estrogen could protect the brain tissue or not, by influencing cerebral edema and expression of Bcl-2 and Bax of impaired brain tissue after traumatic head injury (TBI) in rats.Methods:To select seventy-five adult male Wistar rats of health and clean, then divided into two groups stochastically. In the first group sixty rats were used to detect the expression of Bcl-2, Bax and TUNEL of impaired brain tissue. In the second group fifteen rats were used to detect the water content of brain tissues. Each group was divided into the treated group, the control group and the injury group again.The treated group:TBI model was established according to Feeney's weight-dropping model of traumatic brain injury, and peritoneal injection with benzestrofol (lmg/kg·d), immediately treated once after injury, then treated once per day, until put rat to death. The control group:the model was established by the same way, and peritoneal injection with same dose physiological saline.The injury group:the model was established by the same way but not teated. After all time point coming we put rats to death, the impaired brain tissues were stained with hematine-eosin, to observe morphologica diversity on apoptosis of neuron and detected the expression of Bcl-2 and Bax with immunohistochemistry method, then calculated the expression ratio of Bcl-2 and Bax, cell apoptosis was observed and calculated apoptosis index by TUNEL method,to obtain brain tissue then detected the water content of brain.Results:(1) Observing HE by the light microscope:In the treated group the structure of nerve cell is more complete than the control group and the injury group, has not seen the obvious nerve cell karyopyknosis, nucleus disruption, nearby the nuclear chromatin the collection phenomenon, and the arrangement distribution is even. (2)The expression of Bcl-2 and Bax located in cytoplasm and/or around nuclear, presented buffy. The positive cell with Bcl-2 and Bax mostly located around the injury brain tissue, less located away from injury brain tissues by light microscope. The rate of positive cell with Bcl-2 in the treated group was obviously higher than both the injury group and the control group(P<0.05), but there was no statistics difference between the injury group and the control group(P>0.05). The percentive rate of positive cell with Bax were no statistics difference among the three group (P>0.05). The mean rate of positive cell with Bcl-2 and Bax in the treated group was higher than the control group and the injury group. (3)The positive expression of TUNEL staining was cell nucleus with buffy granule.The apoptosis index in the treated group was less than the control group and the injury group (P<0.05), but there was no obvious difference between the injury group and the control group(P>0.05).(4)The water content of brain in three group had statistics significance (P<0.05) by the mono-factor analysis of variance. Then by compare each other there was statistics significance between treated group and control group (P<0.05), similarly between treated group and injury group, but there was no statistics significance between control group and injury group (P>0.05).Conclusion:(1) The estrogen could promote the expression of Bcl-2 of impaired brain tissue after brain injury, but have not obviously impacted on the expression of Bax. (2)The estrogen could lessen the extent of cerebral edema after brain injury in rats. (3)The estrogen could protect the brain tissue by lessening the extent of cerebral edema and promoting the expression of Bcl-2 of impaired brain tissue after brain injury in rats.