Remodeling and impaired dilation in middle cerebral arteries from Deoxycorticosterone acetate (DOCA)‐salt rats

Abstract

Genetic hypertension causes inward remodeling and impaired dilation in the middle cerebral artery (MCA). DOCA‐salt rats are widely used model of hypertension, yet few studies have been performed on their cerebral arteries. We hypothesized that MCAs from DOCA‐salt hypertensive rats will have a reduced lumen diameter and impaired endothelium dependent dilation. Male Sprague‐Dawley rats had uninephrectomy, and received either DOCA (150mg/kg) and salt water (1% NaCl and 0.2% KCl) or tap water. MCAs were studied by pressure myography. Data are mean±SEM, SHAM vs DOCA. DOCA showed impaired dilation to 10 μM ADP (change from baseline: 41.2±5.2 vs 24.7±4.7%, p< 0.05, ANOVA). Lumen diameter was reduced (295±18 vs 343±13 μm at 80 mmHg, p <0.05, ANOVA) in the DOCA rats. Interestingly the wall/lumen ratio (0.06±0.02 vs 0.07±0.01 at 80 mmHg, p>;0.05, ANOVA) did not change. These data suggest the MCAs from DOCA rats may exhibit inward hypotrophic remodeling. These data are contrary to the inward hypertrophic remodeling observed in MCAs from genetically hypertensive rats and imply that the mechanism of remodeling in DOCA‐salt rats may be different.