Hypertonic/hyperoncotic solution attenuate blood-brain barrier breakdown and brain pathology in whole body hyperthermia rats.

This study was designed to investigate the effects of hypertonic/hyperoncotic solution on blood-brain barrier damage, brain edema and morphological changes of rats during whole body hyperthermia. 90 adult male Sprague-Dawley rats were randomized into 5 groups: Control group (a room temperature for 4 hours); Whole body hyperthermia group without solution treatment; Whole body hyperthermia group with Ringer's solution treatment; Whole body hyperthermia group with hydroxyethyl starch and Ringer's solution treatment; Whole body hyperthermia group with Hypertonic/hyperoncotic solution treatment. All rats except those of control group were housed in a heated container and maintained at 36°C for 3 hours until the rectal temperature reached 41-42°C. Corresponding solutions were administered intravenously at the beginning of whole body hyperthermia within 30 minutes as designed. Following whole body hyperthermia, rats were subsequently cooled down for 1h. Evans blue was administered intravenously when the rectal temperature was cooled down to 37°C. The leakage of Evans blue-albumin and water content of brain were calculated and morphological changes were investigated. In group with hypertonic/hyperoncotic solution treatment, brain water content and the leakage of Evans blue-albumin were the lowest among the four whole body hyperthermia groups. Compared with the other three whole body hyperthermia groups, in which profound to moderate damages to blood-brain barrier and brain tissue and cells were found, there were only slight morphological changes in the group with hypertonic/hyperoncotic solutionon treatment. Treatment with hypertonic/hyperoncotic solution appeared to attenuate the injury to blood-brain barrier and reduce brain edema and cell morphological changes in whole body hyperthermia rats.