RESUMO
Objective To investigate the effects of dexamethasone (DEX) on vascular endothelial growth factor( VEGF) in cerebrospinal fluid of rabbits with bacterial meningitis. Methods A total of 36 rabbits were assigned to study,which were randomly divided into meningitis model group (MOD) .dexametha-sone-treated group (DEXT) and control group( CON). CSF was sampled for determining at 6 h, 12 h and 24 h after injection of E. coli suspension. The concentration of VEGF in every CSF sample was determined quantitatively by ELISA. Results There were higher concentrations of CSF VEGF at6h,12h and 24hin M0D(( 1219 ±176) ng/L,( 1343 ±160) ng/L,(981 ±134) ng/L) than that in CON( (374 ±172) ng/L, (370 ± 169) ng/L,(367 ± 171) ng/L) (P<0.01). There was higher brain water content in M0D( (80.8 ± 0.5) % ) than that in CON( (80.0 ± 0.5) % ) (P < 0.01). There was positive correlation between the brain water content and the concentration of CSF VEGF at 24 h( r - 0.919,P < 0.01). Compared with MOD, the concentrations of CSF VEGF in DEXT at 6 h, 12 h,24 h ((941 ±147) ng/L, (1083 ± 123) ng/L, (825 ± 66) ng/L) were decreased significantly(P <0.05), the brain water content was less ((80.4 ±0.5) %) (P < 0.05). Conclusion The secretion of VEGF markedly increases in the pathological process of bacterial meningitis. VEGF contributes to the damage of blood brain barrier and the formation of brain edema. DEX can decrease the degree of brain edema by suppressing the generation of VEGF and lightening the damage of blood brain barrier.
