Comparison of Cognitive Performance and Cardiac Function Between Three Different Rat Models of Vascular Dementia

Establishing an ideal animal model is essential for studying the pathogenesis, prevention and treatment of vascular dementia (VD). The present study was designed to compare the differences of behavior, cerebral blood flow (CBF), cardiac output and the levels of myocardial enzyme of three different VD rat models.

The rats were randomly divided into sham-operated group (SHAM), permanent bilateral common carotid artery occlusion group (BCCAO), BCCAO combined with sodium nitroprusside (2.0mg·kg^-1) group (BCCAO+2.0SNP) and BCCAO combined with sodium nitroprusside (2.5mg·kg^-1) group (BCCAO+2.5SNP). After operation, Morris water maze test, echocardiographic evaluation and the measurement of CBF were performed, then the levels of myocardial enzymes in serum were assessed during euthanasia.

Compared with SHAM rats, the three VD model rats showed different degrees of cognitive impairment, lower cardiac output and CBF, and BCCAO rats showed higher levels of myocardial enzymes. Compared with BCCAO rats, the spatial learning ability of BCCAO+2.0SNP rats and BCCAO+2.5SNP rats was more severely impaired, while the levels of myocardial enzymes of BCCAO+2.0SNP rats were lower. Compared with BCCAO+2.0SNP rats, BCCAO+2.5SNP rats showed no significant difference in cognitive function and cardiac function.

Our present study demonstrated that all of the three different VD rat models exhibited cognitive and cardiac function impairment. The BCCAO+2.0SNP model and BCCAO+2.5SNP model damaged the spatial learning ability more seriously. The BCCAO+2.5SNP model caused more comprehensive cognitive impairment. In addition, the BCCAO+2.0SNP model and BCCAO+2.5SNP model might cause more serious damage to cardiac function.