To investigate the protective effect of limb remote ischemic postconditioning (RIPostC) on vascular cognitive impairment (VCI).

According to random number table, twelve healthy male C57BL / 6J mice were randomly divided into 3 groups: sham operation group (sham group, n=4), model control group (BCAS group, n= 4) and model-distal ischemia group (BCAS + RIPostC group, n=4). The bilateral carotid artery stenosis (BCAS) was used to produce mice model. Two weeks after the BCAS surgery, BCAS + RIPostC mice were treated with RIPostC at the same time for 5 minutes, repeated 4 times a day for 2 weeks. And morris water maze test was used to test the cognitive function. HE staining was used to detect pathological changes of white matter in each group at the same time. The expression of Beclin-1 protein in the white matter was detected by Western blot.The repeated measurement ANOVA was used to analyse verage escape latency of mice. The remaining data were analyzed by one-way ANOVA, LSD-t test was used to compare two groups.

Twenty eight days later , The water maze test showed that the BCAS group and the BCAS + RIPostC group had a longer escape latency than the BCAS group(P>0.05). Compared with the sham group, The mean escape latency of RIPostC group was shortened(P>0.05). HE staining showed that RIPostC could improve the degree of white matter damage induced by BCAS. Western blot showed that the expression of Beclin-1 in BCAS group and BCAS + RIPostC group was significantly higher than that in sham group (P <0.05), and the expression of Beclin-1 in BCAS + RIPostC group increased more significantly (P <0.05).

RIPostC can reduce the damage of brain white matter caused by BCAS, and the neuroprotective effect of RIPostC may be related to the autophagy pathway.