Effect of human urinary kallidinogenase on cognitive function of SAMP8 mouse model and its mechanism / 中国药理学通报

ABSTRACT

Aim To study the effect of human urinary kallidinogenase(HUK)on the cognitive function of SAMP8 mouse model and its mechanism. Methods SAMP8 mice were divided intofive groups:SAMP8 group,treatment group(giving 8.75×10-3,1.75×10-2,3.5×10-2,7.0×10-2 HUK),and the SAMR1 vehicle group was used as blank control. Each group was performed Morris water maze to detect spatial cognition. Afterwards the group with the most obvious cognitive improvement(HUK group)was selected for the follow-up experiments. Immunohistochemical detection of ChAT expression in CA3 area was further verified by RtPCR. Western blot was used to detect the expression of PSD95,SYN,BDNF,and pCREB protein. The activity of MPO and the content of IL-1β and IL-18 were determined. Results The passing times in the SAMP8 group was less than that of the SAMR1 group(P<0.05). The passing times of treatment group increased compared with the SAMP8 group(P<0.05 or P<0.01),and the spatial probe time of the target quadrant was shorter(P<0.05 or P<0.01). We conducted follow-up experiments with group d(HUK group). The expression of ChAT positive cells in CA3 area of SAMP8 group was significantly lower than that of SAMR1 group; the expression of positive cells in HUK group significantly increased; RtPCR showed that ChAT expression in SAMP8 group was lower than that in SAMR1 group,and ChAT expression was significantly higher than that in SAMP8 group after HUK treatment. Compared with the SAMR1 group,the levels of IL-1β,IL-18 and MPO activity in the CA3 area of SAMP8 group significantly increased,and the protein expressions of PSD95,SYN,BNDF and pCREB decreased. After HUK treatment,the content of IL-1β,IL-18 and MPO activity decreased,and the expression of PSD95,SYN,BNDF and pCREB increased. Conclusions HUK can improve the spatial cognition of SAMP8 mice. The mechanism may be achieved by promoting the expression of ChAT in CA3 area,reducing the oxidative stress and increasing synapse-related proteins.