The Study Of Astragaloside IV After Intracerebral Hemorrhage About Aquaporin 4 Expression And Brain Edema In Rats

Objective By looking into how Astragaloside IV(ASG) affect the degree of edema after ICH of rat and aquaporin 4(AQP4) expression, to investigate ASG regulate mechanism of edema after ICH.Method Healthy male SD rats were randomly divided into control group, ICH model group and the ASG treatment group. Each group of rats were putting into following research separately at 1,2,3,5,7d time point after ICH: 1. Using Bederson standard to measuring neurobehavioral neurological score of rats from these experimental groups; 2. The application of Nissl and HE staining were used for observing the morphology of cells surrounding focus;3. Using the wet and dry weight method to measure brain tissue’s water content of each group of rats; 4. Immunohistochemistry technique was used to detect AQP4 expression positive cell number in experiment groups of rats, Immunofluorescence showed the changing trend of astrocytes and AQP4 expression after ICH; 5. Using Western blot method to detect AQP4 expression level in brain tissue around hemorrhage focus.Result 1. Neuroethology score: Rats from ICH model group and ASG group both showed the symptoms of limb hemiplegia, while the control group was normal; The comparison of ICH model group and ASG group suggest that there was no significant differences between groups at 1d time point(P>0.05), but at 3d and 7d time point, the scores of ASG group was significantly lower than ICH model group(P<0.05). 2.Morpholgy observation of the cells surrounding ICH focus: The results suggest that the cellular morphology and structure of the cell were both normal in control group; The surrounding tissues of hemorrhage focus in ICH group were seriously damaged, and appear to be cellularstructure disorder, broken neurons and the number is reduced, fragmentation of the nucleus,and all these situation got to peak value at 3d time point, and the morphology of cells in ASG group at 3d and 7d time points was improved than the ICH model group. 3. Dry-wet weight method test results: the ICH model group rats brain tissue edema degree in 1d, 2d and 3d time points were significantly higher than that of control group(P < 0.01), while in the 5d, 7d time points difference between the two groups was not significant(P > 0.05); the rat brain tissue water content of ICH model group in 1, 2, 3d time point were significantly higher than 5, 7d time points(both P < 0.05); there were also significant differences between 1d and 2d time point of ICH model group(P< 0.05); ASG group rats edema degree only in 2d time points was significantly higher than that of control group(P < 0.05), and in 2d, 3d time points the edema degree were significantly lower than that in ICH model group(P<0.05). 4.Immunohistochemical detection results: AQP4 positive cell count in rats of ICH model group and ASG group at various time points were significantly higher than that of control group(P <0.05), peak value appeared in 2d time point. AQP4 positive cell count in ASG group rats were significantly lower than ICH model group in each time point besides 1d time point(P < 0.05).5. Immunofluorescence test results: AQP4 expression in astrocytes, in 1,3,5d time point,astrocytes count of ASG group was significantly higher than that of ICH model group(P <0.01); AQP4 positive cells count in ASG group at 1d time point showed no significant difference to that of ICH model group(P > 0.05), but that of 3, 5d time points were lower than ICH model group, and with statistical significance(P < 0.01). 6. Western blot results: Only a small amount of AQP4 protein expressional in normal control group, AQP4 protein expression in control group at different time points were significantly lower than ICH model group and ASG group(P < 0.05); the comparition between ICH model group and other to groups, the result showed that the AQP4 expression 2d time point is significantly higher than other time points(P < 0.01); AQP4 expression quantity in ASG group were lower than the ICH model group, with statistical significance(P < 0.05), except at the 1d time point.Conclusion 1. AQP4 expression in after ICH edema period of rats were significantly increased, and reaches its peak at 2d time point; 2. the expression of AQP4 in the cells surround ICH focus were significantly correlated to the edema degree of cells; 3. In the treatment of ICH, ASG can significantly decrease the expression of AQP4 in rats after ICH,and could significantly reduce the degree of edema in the brain tissue around hemorrhage focus; 4. The mechanism of ASG function to cerebral edema may be formed by reducing the expression level of AQP4 in the cell.