Effect of diazepam on blood-brain barrier after radiation-induced brain injury in rats
- VernacularTitle:地西泮对放射性脑损伤大鼠血脑屏障的影响
- Author:
Chen WANG
;
Hong XIE
;
Ye TIAN
- Publication Type:Journal Article
- Keywords:
Diazepam;
Radiation injuries,experimental;
Brain injuries;
Blood-brain barrier
- From:
Chinese Journal of Anesthesiology
1997;0(11):-
- CountryChina
- Language:Chinese
-
Abstract:
Objective To investigate the effect of diazepam on blood-brain barrier ( BBB ) after radiation-induced brain injury. Methods Two hundred and forty healthy male SD rats weighing 240-270 g were randomly divided into 4 group with 60 animals in each group: Ⅰ D-R group received intraperitoneal diazepam 5 mg?kg-1 30 min before irradiation; Ⅱ N-R group received no diazepam before irradiation; Ⅲ D-SR group received intraperitoneal diazepam 5 mg? kg-1 30 min before sham irradiation and Ⅳ N-SR group received no diazepam before sham irradiation. The animals were placed in a prone position awake without any anesthetics. The whole brain was irradiated by 4 MeV electron beam at a single dose of 30 Gy. The changes in BBB were assessed by (1) magnetic resonance imaging (MRI) with the T1-weighted images, T2-weighted images and MRI enhancement images induced by Gd-DTPA; (2) Evans blue (EB) assay; 2% EB 3 ml?kg-1 was injected via femoral vein and 3 h later the animals were decapitated and EB content in the brain tissue was determined by spectrophotometry; (3) The expression of vascular endothelial growth factor (VEGF) in the brain tissue determined by immuno-histochemistry before irradiation ( T0 ) ( baseline) at 6 h (T1 ), 1 day ( T2 ) , 1 week ( T3 ) and 1 month ( T4 ) after irradiation.Results In group Ⅱ (no diazepam before irradiation) the signal intensity of T1-weighted images significantly decreased while the signal intensity of T2-weighted images and the enhancement rate significantly increased at T4. However in group Ⅰ (diazepam was given before irradiation) the changes in the MRI were significantly attenuated. The EB content at T1, T3 , T4 and the expression of VEGF at T1 , T, were significantly higher in group Ⅱ than in group Ⅰ . Conclusion Diazepam given before irradiation can protect BBB against irradiation injury by decreasing the expression of VEGF in the brain tissue and BBB permeability.
