Obesity is a risk factor for stroke, but the determinants of increased stroke risk in obesity are unknown. We have previously reported that obese Zucker rats (OZR) have a worse stroke outcome and display evidence of remodeling of the middle cerebral artery (MCA), in parallel with hypertension, compared to lean controls. This study tested the hypothesis that hypertension is an essential determinant of cerebral vascular remodeling and increased stroke damage in OZR. Blood pressure was measured by telemetery in lean and obese rats +/- hydrochlorthiazide (HCT, 2 mg/kg/day) from 8 to 15 weeks of age. A separate group of rats was also chronically fed a low sodium (LS) diet. Vessel structure was assessed in isolated, pressurized MCAs. Cerebral ischemia was induced for 60 minutes using an intralumenal suture technique, followed by 24 hours of reperfusion. HCT treatment effectively prevented the increase in blood pressure in obese rats, however, the LS diet did not lower pressure. Importantly, infarct size was normalized by HCT following ischemia/reperfusion injury. Additionally, HCT improved the changes in MCA structure observed in untreated OZR. There were no benefits of the LS diet on stroke injury or vessel structure. These results indicate that increased pressure is essential for driving the changes in infarct size in OZR.
- Copyright © 2009, American Journal of Physiology - Heart and Circulatory Physiology