Mohammadi M T, Dehghani G A. Intensification of brain injury and blood-brain barrier permeability by short-term hypertension in experimental model of brain ischemia/reperfusion. Physiol Pharmacol 2014; 18 (1) :110-121
URL:
http://ppj.phypha.ir/article-1-963-en.html
Abstract: (10290 Views)
Introduction: Arterial hypertension is one of the causes of stroke, and as one of the vasculotoxic conditions
intensifies ischemic stroke complications. The aim of the present study was to analyze the effects of short-term cerebral
hypertension on ischemia/reperfusion injury and pathogenesis of ischemic stroke.
Methods: The experiments were performed on three groups of rats (N=36) Sham, control ischemia and
hypertensive ischemia. Rats were made acutely hypertensive by abdominal aortic coarctation, and after 8 days, were
randomly selected for cerebral ischemia induced by middle cerebral artery occlusion (MCAO) for 60 min followed by
12 h reperfusion. The rats were slaughtered under deep anesthesia for measurement of cerebral injury area by
triphenyltetrazolium chloride staining method or blood-brain barrier (BBB) integrity disruption by Evans blue
extravasation technique.
Results: Arterial pressure was increased >36% in hypertensive rats, and blood flow of the ischemic region was
reduced by 80% in the ischemic groups compared with the sham. MCAO induced infarction in large areas of the right
hemisphere in hypertensive rats compared with control ischemic rats, and subcortical infarct volume was significantly
more in ischemic groups (236±43 vs. 139±25 mm3). MCAO also increased Evans blue extravasations in hypertensive
rats (9.48±2.03 μg/g) more than non-hypertensive rats (5.09±1.41 μg/g).
Conclusion: The findings of present study indicate that the short-term hypertension intensifies the
ischemia/reperfusion-induced brain injuries. This type of hypertension also causes severe damage in BBB function and
enhanced cerebrovascular permeability after brain ischemia.