Hypertonic saline ameliorates cerebral edema through downregulation of aquaporin-4 expression in the astrocytes.
Osmotherapy with 10% hypertonic saline (HS) alleviates cerebral edema through osmotic force. Aquaporin-4 (AQP4) has been reported to be implicated in the pathogenesis of cerebral edema resulting from a variety of brain injury. This study aimed to determine if 10% hypertonic saline ameliorates cerebral edema through downregulation of AQP4 expression in the perivascular astrocytes in the ischemic cerebral edema. Adult male Sprague-Dawley (SD) rats were subjected to permanent right-sided middle cerebral artery occlusion (MCAO) and treated with a continuous i.v. infusion of 10% HS. Brain water content (BWC) analyzed by wet-to-dry ratios in the ischemic hemisphere of SD rats was attenuated after 10% HS treatment. This was coupled with the reduction of neuronal apoptosis in the peri-ischemic brain tissue. Concomitantly, downregulated expression of AQP4 in the perivascular astrocytes after 10% HS treatment was observed. Our results suggest that in addition to its osmotic force, 10% HS exerts anti-edema effects possibly through downregulation of AQP4 expression in the perivascular astrocytes. The reduction of brain edema after 10% HS administration can prevent ischemic brain damage.
Zeng
H K
HK
Department of Emergency & Critical Care Medicine, Guangdong General Hospital, Guangdong Academy of Medical Sciences, 106 Zhongshan Er Road, Guangzhou 510080, PR China. zenghongke@vip.163.com
Wang
Q S
QS
Deng
Y Y
YY
Fang
M
M
Chen
C B
CB
Fu
Y H
YH
Jiang
W Q
WQ
Jiang
X
X
D000818:Animals; D017209:Apoptosis; D051401:Aquaporin 4 / Q000096:biosynthesis* / Q000235:genetics; D001253:Astrocytes / Q000378:metabolism*; D001921:Brain / Q000378:metabolism / Q000473:pathology; D001929:Brain Edema / Q000209:etiology / Q000378:metabolism / Q000628:therapy*; D015536:Down-Regulation; D020244:Infarction, Middle Cerebral Artery / Q000150:complications; D008297:Male; D009474:Neurons / Q000473:pathology; D009995:Osmosis; D012333:RNA, Messenger / Q000096:biosynthesis; D051381:Rats; D017207:Rats, Sprague-Dawley; D012462:Saline Solution, Hypertonic / Q000494:pharmacology* / Q000627:therapeutic use
D051401:Aquaporin 4; D012333:RNA, Messenger; D012462:Saline Solution, Hypertonic