The expression of aquaporin-4 in the ischemic penumbra tissues after acute cerebral ischemia in rats
- VernacularTitle:水通道蛋白-4在脑缺血半暗带组织中的表达
- Author:
Hong LU
;
Renping XIONG
;
Hui HU
;
Jiannong ZHAO
;
Yan ZENG
;
Cong YU
;
Wei GAN
;
Jie LI
;
Weibo XIE
;
Weiguo NI
;
Fajin LV
;
Xiangchen CHENG
- Publication Type:Journal Article
- Keywords:
Aquaporins;
Brain ischemia;
Model, animal;
Magnetic resonance imaging
- From:
Chinese Journal of Radiology
1994;0(06):-
- CountryChina
- Language:Chinese
-
Abstract:
Objective The aim of this study was to investigate the aquaporin-4(AQP4) expression in the ischemic penumbra tissues.Methods Thirty-six Wistar rats were divided into 7 groups randomly, including control group(n=6) and occluded groups(n=30). The occluded groups were studied after the right middle cerebral artery of the rats unilaterally occluded(MCAO) at an interval of 15 min, 30 min, 1 h, 3 h, 6 h and 24 h, respectively(n=5 for each group). The operation process of the control group was the same as the occluded group except occluded MCAO. Then all rats were imaged with T_1WI, T_2WI and diffusion weighted-imaging(DWI). The brain tissue, according to the method by LIU Meili reported, was regarded as the area of the graphic penumbra. The relative apparent diffusion coefficient of the graphic-penumbra (rADC_1) and the center infarction(rADC_2)(ratios between the values of the occluded side and the opposite side) were calculated. The animals were sacrificed and perfused with the mixture solution consisting of TTC at different time intervals. The graphic-penumbra of the biggest layer of the ischemic cerebral tissue which corresponded to the DWI was examined with immunohistochemistry and RT-PCR. Meanwhile, histologic examination was performed at same site of the lesion. Results There were no significant changes on MRI, the relative apparent diffusion coefficient and the expression of the AQP4. The abnormal high intensity was found on DWI at 15 min after MCAO. T_2WI detected the lesion at 1 h after MCAO. The value of the rADC_1 decreased within 24 h after MCAO in ischemic penumbra, especially, it descended quickly within 1 h after MCAO, from(70.4?6.9)% at 15 min to(53.5?10.9)% at 1 h. Whereas, in the infarct tissue, the changes of the rADC_2 had a rule of decrease from(71.5?6.6)% at 15 min to(45.7?10.5)% at 3 h at first time, and then follow an increasing up to(78.7?11.5)% at 24 h after MCAO. The expression of AQP4 increased gradually within 24 h after MCAO, from 0.42?0.05 at 15 min to 1.18?0.12 at 24 h, it showed negative relationship with the rADC_1 in the ischemic penumbra (r= -0.966,P
