The effect of hypertension on ischemic cerebral edema in spontaneously hypertensive rats

Cerebral ischemia was produced in spontaneously hypertensive rats (SHR) with a range of blood pressures (BP). Measurements were made at 4 hours of the edema produced (% H2O), the damage to the blood brain barrier (BBB) and, the blood flow (CBF) in both hemispheres and the cerebellum and brain stem. There was a statistically significant correlation between CBF and BP and between CBF and % H2O, but the correlation between BP and % H2O was not significant. The BBB is not open to technecium pertechnetate in this model at this time interval. Systemic hypertension is not a significant factor in the early development of ischemic edema in this model because the blood flow in the ischemic area falls with rising blood pressure, probably due to autoregulation in the collateral circulation.