Aquaporin-4 and ischemic brain edema

OBJECTIVE:To investigate the relationship of aquaporin 4(AQP4)and brain edema.DATA SOURCES:Using the terms of "aquaporin-4,brain edema",we searched PubMed database to identify studies published from January 1997 to April 2006 in the English languages.Meanwhile,we also searched China National Knowledge Infrastructure(CNKI)for related studies.STUDY SELECTION:The collected data were selected firstly.Studies on AQP4 and brain edema were chosen and their full-texts were searched for,and those with repetitive or review studies were excluded.DATA EXTRACTION:Totally 146 related studies were collected,42 of them were involved and the other 104 studies were used for reading reference data.DATA SYNTHESIS:AQP4 is a selective water permeable integral membrane protein.It is mainly expressed in astrocytes and ependymocyte,and is the important structural basis for water regulation and transportation between glial cells and cerebrospinal fluid or vessels.Phosphorylation is involved in the regulation of AQP4.AQP4 participates in the formation of brain edema caused by various factors.Studies on the structure and pathological changes of AQP4 are still in the initial stage,and the role and mechanism of AQP4 in the formation of brain edema is very unclear.CONCLUSION:AQP4 plays a critical regulating role in the formation of ischemic brain edema,but whether it is regulated by drugs lacks reliable evidence.