Effects of different doses of propofol on traumatic brain injury in rats

Objective To evaluate the effects of different doses of propofol on traumatic brain injury in rats .Methods Forty-eight healthy male Sprague-Dawley rats , aged 7-8 weeks , weighing 270-320 g , were randomly divided into 6 groups （ n=8 each ） using a random number table ：sham operation group （group S ） , traumatic brain injury group （group I） ,fat emulsion group （group F） and low-dose propofol group （group L） , medium-dose propofol group （group M ） ,and high-dose propofol group （group H ） .Traumatic brain injury model was established according to the method described by Feeney .In group S ,0.9% normal saline was infused into the left femoral vein at 3.49 ml·kg-1 ·h-1 .In I ,F ,L ,M and H groups ,0.9% normal saline ,20% fat emulsion 3.49 ml·kg-1 ·h-1 ,and propofol 17.46 ,34.92 and 69.84 mg·kg-1 ·h-1 were infused into the left femoral vein ,respectively .Blood samples were collected from the right common carotid artery at 15 and 60 min of infusion （T1-2 ） for determination of serum S100β protein concentrations . The rats were then sacrificed after collecting blood samples at T2 and brains were removed for microscopic examination of the pathological changes of the cerebral cortex （light microscope ） and ultrastructure of neurons in the cerebral cortex （transmission electron microscope） .Results The serum S100β protein concentrations were significantly higher at T1 ,2 in the other five groups than in group S （ P〈0.05 ） .Compared with I and F groups ,the serum S100βprotein concentrations were＆nbsp;significantly decreased at T1 ,2 in L ,M and H groups （ P〈0.05） .Compared with group L ,the serum S100βprotein concentrations were significantly decreased at T2 in M and H groups , and the serum S100β protein concentrations were increased at T1 in H group （ P〈 0.05 ） . The serum S100β protein concentrations were significantly higher at T1 ,2 in H group than in group M （ P〈0.05 ） .Light microscopic examination showed that nucleus condensation , cell necrosis , and cell edema were significantly attenuated in L ,M , and H groups as compared with group I;normal neurons could be found in group M .Transmission electron microscopic examination showed that the severity of neuronal damage was significantly attenuated in L ,M ,and H groups as compared with group I .Conclusion Different doses of propofol can reduce traumatic brain injury in rats . Key words: Propofol; Brain injuries