Background and Purpose: Chronic remote ischemic conditioning (C-RIC) is effective at improving cerebral blood flow (CBF) inducing vascular remodeling, and improving cognition in a bilateral carotid artery stenosis (BCAS) mouse model, a model for Vascular Cognitive Impairment and Dementia (VCID). This improvement is associated with elevations of plasma nitrite. Our aim was to determine if the beneficial effect of C-RIC was eNOS dependent.
Methods: Microcoil (01.8 mm) induced BCAS model was used to induce chronic hypoperfusion. Adult eNOS-KO male mice (5-6 months) were randomly assigned to 2-groups (N=5): (1) BCAS and (2) BCAS+RIC. RIC was started 7d post-surgery daily for 3 weeks. Behavioral test and CBF was performed before termination. Functional outcomes were assessed using novel object recognition (NOR) test for non-spatial working memory, and hanging wire and beam walk test for motor/muscular impairment. Mice were followed for 4 weeks.
Results: C-RIC-therapy for 3 weeks did not improve CBF in the BCAS+RIC groups at either a 2nd weeks or 4th weeks compared to BCAS-Sham RIC groups. There was no significant change between the BCAS and BCAS+RIC groups in the discrimination index as determined by the NOR test or poor motor function as determined by hanging wire and beam walk test.
Conclusions: The beneficial effect of C-RIC in the BCAS model is abrogated in eNOS KO mice indicating that the effect of C-RIC is eNOS dependent.