Study on hyperbaric oxygen preconditioning against anoxic brain edema of mice

Abstract

Objective Water content, total natrium and calcium content of mice brain were detected to evaluate prevention effect of hyperbaric oxygen （HBO） exposure on the mice brain edema. Evans blue content of mice brain tissue was detected to investigate the effects of HBO on brain edema. Methods Forty-eight male Kunming mice with weight of 22-25 （22. 5±2.31）g were randomly divided into 4 groups：HBO group, hyperbaric air （HBA） group, normal baric air （NBA） group, and blank control （BC） group. HBO group, HBA group and NBA group were exposed to designed air environment respectively, twice daily for 3 successive days. Twenty-four hours after the last exposure and under same situation, these 3 groups were exposed to hypomia for 12 hours. Water content of mice brain tissue were detected by means of analytic balance, and dry and wet weight were compared. Measurement of total natrium, total calcium adopted wet calcination of brain tissue and atomic absorption spectroscopical spectroscopy. Measurement of Evans blue （EB） content adopted formamide method. Results Compared with NBA group, water content of brain tissue had no significant statistical difference in HBA group. Compared with HBA group, water content, total natrium, total calcium and EB content of brain tissue were significantly reduced （P〈0. 01）. Conclusions HBO preconditioning can prevent brain edema causing by acute hypoxia, but increasing pressure alone during air preconditioning can not prevent brain edema. Key words: Hyperbaric oxygenation; Anoxia; Brain edema