[Research on acting mechanism of rhubarb on aquaporin-4 in rats with blood-brain barrier injury after acute cerebral hemorrhage].
OBJECTIVE
To investigate the mechanism of rhubarb in regulating aquaporin-4 in rats with blood-brain barrier damage after acute cerebral hemorrhage (CH).


METHODS
CH model was induced by stereospecific injection of auto-blood into caudate nucleus of rats, and the brain water content and neurological defect were detected to evaluate cerebral edema and neurological defect level. Also, the blood-brain barrier damage was observed by Evan's blue staining; the changes of blood-brain barrier tight junction and astrocyte end feet at different time points were observed with electron microscope; and the AQP-4 mRNA and protein expression were measured with RT-PCR and Western blot.


RESULTS
Rhubarb showed effects in reducing cerebral edema. Evan's blue result indicated the blood-brain barrier was evidently damaged at the 12th hour after CH, with blood-brain barrier tight junction damaged and astrocyte end feet process swelled obviously, but these changes could be relieved by rhubarb. The AQP-4 mRNA and protein expression in rats increased significantly 24 hrs after modeling (P < 0.05) and reached the peak value at 72 hrs, and decreased gradually after then. Rhubarb also showed inhibiting transcription and translation of AQP-4 gene.


CONCLUSIONS
Rhubarb could alleviate cerebral edema via reducing blood-brain barrier tight junction damage and astrocyte end feet process swelling, which might be realized by the inhibition on transcription and translation of AQP-4 gene.
Tang
Yu-ping
YP
Zhongshan Hospital Affliated to Shanghai Medical College, Fudan University 200032.
Cai
Ding-fang
DF
Liu
Jun
J
D000818:Animals; D051401:Aquaporin 4 / Q000096:biosynthesis* / Q000235:genetics; D001812:Blood-Brain Barrier / Q000187:drug effects*; D001929:Brain Edema / Q000188:drug therapy / Q000209:etiology; D002543:Cerebral Hemorrhage / Q000188:drug therapy* / Q000378:metabolism / Q000503:physiopathology; D004365:Drugs, Chinese Herbal / Q000627:therapeutic use; D008297:Male; D008517:Phytotherapy; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D011897:Random Allocation; D051381:Rats; D017207:Rats, Sprague-Dawley; D012250:Rheum
D051401:Aquaporin 4; D004365:Drugs, Chinese Herbal; D012333:RNA, Messenger