Renovascular hypertension causes cerebral vascular remodeling

Background and purpose. Hypertension is the greatest risk factor for cerebral ischemia stroke. Whether hypertension aggravates the ischemia injury during cerebral infarction or delay the recovery of cerebral infarction is still unknown. This study aims to investigate the pathphysiological effect of hypertension on microvascular structure and how it affects the recovery of cerebral infarction. Methods. Renovascular hypertensive rats (RHRs) were developed with 2-kidney, 2-clip method. Permeability of cerebral surface blood vessels, cerebral vascular casts and histopathological examination were performed to assess the histopathophysiology of cerebral vascular structure. Stroke damage was assessed by calculation of infarct volume after ischemia induced by middle cerebral artery occlusion. Results. All RHRs 10 weeks displayed high permeability of cerebral surface blood vessels. Vascular cast of RHRs showed that vascular network was sparse. The arterioles of RHRs 10 weeks had smaller lumen diameter, but thicker vessel wall with hyalinosis formation. After ischemia, the infarction size was larger in RHRs than control animals. Conclusions. The cerebral arterioles of RHRs underwent structural remodeling. High blood pressure may aggravate the severity of brain injury in cerebral ischemia and affect the recovery of ischemia.