Brain functions and unusual β-amyloid accumulation in the hypertensive white matter lesions of rats

Abstract

This study used Sprague Dawley (SD) rats with stroke-prone renovascular hypertension (RHRSP) to establish an animal model of hypertensive white matter lesions (WML), so as to explore the brain functions and unusual β-amyloid (Aβ) accumulation in WML. Hypertensive WML and brain dysfunctions were evaluated by measuring the caudal arterial pressure of model rats, and by observing the histomorphological deformations o f the prefrontal lobe, temporal lobe, hippocampus and corpus callosum, as well as by counting of the number of neurons using Hematoxylin and Eosin (H and E) staining, and by evaluating the changes in rat brain functions, including memory and the ability of visual space learning, using the Morris Water Maze Test. In addition, the study discussed the correlation between Aβ accumulation and hypertensive WML cognitive impairment by adopting an enzyme-linked immunosorbent assay (ELISA) to detect the level of Aβ 1-42, and by detecting the expression of amyloid precursor protein (APP) and Beta-secretase 1 (BACE1) using Western blot. Results of the study showed that at 4 weeks, 8 weeks, 12 weeks and 16 weeks after operation, the blood pressure and brain Aβ expression in the rats of the model group notably increased (P less than 0.01), along with deformed and degenerated brain tissues, confirming that the unusual Aβ accumulation may participate in the occurrence and development of hypertensive WML as well as the induction of cerebral cognitive decreases.