[A aquaporin 4 expression and effects in rat hippocampus after microwave radiation].
OBJECTIVE
To investigate the expression of aquaporin 4 (AQP4) after microwave exposure and the correlation with the brain injury by radiation.


METHODS
70 male rats were exposed to microwave whose average power density was 0, 10, 30 and 100 mW/cm(2) respectively. Rats were sacrificed at 6 h, 1 d, 3 d and 7 d after exposure. Immunohistochemistry and Western blot were used to detect the expression of AQP4 in protein level in rat hippocampus, and the expression of AQP4 in gene level was measured by in situ hybridization and RT-PCR.


RESULTS
The expression of AQP4 in rat hippocampus was abnormal after 10, 30, 100 mW/cm(2) microwave exposure. The protein level showed increased at first and then recovered at 10 and 30 mW/cm(2) groups, while increased progressively in 100 mW/cm(2) group within 14 d (P < 0.01). The gene expression of AQP4 was increased (0.51 +/- 0.02) at the beginning (6 h) and then regained after 10 mW/cm(2) microwave exposure, while in 30 and 100 mW/cm(2) groups, it rose to the peak at 7 d (0.46 +/- 0.02 and 0.43 +/- 0.08) and didn't get back (P = 0.004; P = 0.012).


CONCLUSIONS
Microwave radiation can increase the expression of AQP4 in rat hippocampus. The change might participate in the process of increasing permeability of blood-brain barrier and lead to the brain edema after microwave radiation.
Institution of Radiation Medicine, Academy of Military Medical Sciences, Beijing 100850, China.
Xiang
X
Li
Xiang-jun
XJ
Hu
Rui-yun
RY
Peng
Ya-bing
YB
Gao
Shui-ming
SM
Wang
Li-feng
LF
Wang
Xin-ping
XP
Xu
Zhen-tao
ZT
Su
Guo-shan
GS
Yang
D000818:Animals; D051401:Aquaporin 4 / Q000235:genetics / Q000378:metabolism*; D006624:Hippocampus / Q000378:metabolism* / Q000528:radiation effects; D008297:Male; D008872:Microwaves / Q000009:adverse effects*; D051381:Rats; D017208:Rats, Wistar
C496032:Aqp4 protein, rat; D051401:Aquaporin 4