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Updated: Feb 24, 2026
Evaluation of Cerebral Blood Flow Autoregulation in the Rat Using Laser Doppler Flowmetry
Published on: January 19, 2020
Carotid artery stenosis in hypertensive rats impairs dilatory pathways in parenchymal arterioles
Nusrat Matin1, Courtney Fisher1, William F Jackson1
1Department of Pharmacology and Toxicology, Michigan State University , East Lansing, Michigan.
Insights
Bilateral common carotid artery stenosis (BCAS) impairs parenchymal arteriole function and structure in hypertensive rats, contributing to vascular cognitive impairment. Epoxygenase inhibition may restore function, offering therapeutic targets for cognitive decline.
Area of Science:
- Neuroscience
- Cardiovascular Science
- Pathology
Background:
- Hypertension is a key risk factor for vascular cognitive impairment.
- Carotid artery stenosis exacerbates cognitive decline by reducing cerebral blood flow.
- Parenchymal arterioles (PAs) are critical for regulating cerebral blood flow and are implicated in cognitive function.
Purpose of the Study:
- To investigate the impact of chronic cerebral hypoperfusion (induced by BCAS) on PA function and structure in stroke-prone spontaneously hypertensive rats (SHRs).
- To identify potential therapeutic targets for cognitive impairment in hypertensive individuals at risk for cerebrovascular disease.
Main Methods:
- Utilized pressure myography to assess endothelium-dependent dilation in PAs from BCAS-treated SHRs and sham-operated controls.
- Investigated the roles of nitric oxide (NO), prostaglandins, and epoxyeicosatrienoic acids (EETs) in PA function.
- Examined PA structural remodeling using histological analysis.
Main Results:
- BCAS induced significant endothelial dysfunction in PAs of SHRs, characterized by impaired dilation.
- Inhibition of NO and prostaglandins did not restore PA dilation in BCAS rats.
- Inhibition of epoxygenase significantly increased PA dilation in BCAS rats, suggesting a restored NO/prostaglandin-independent pathway.
- PAs from BCAS rats exhibited structural remodeling with reduced wall thickness.
Conclusions:
- Chronic cerebral hypoperfusion in hypertensive rats leads to marked endothelial dysfunction and structural remodeling of PAs.
- Epoxygenase inhibition may represent a novel therapeutic strategy to improve PA function and potentially mitigate vascular cognitive impairment.
- These findings highlight the critical role of PA dysfunction in the development of cognitive deficits associated with hypertension and hypoperfusion.
Abstract:
Hypertension is a leading risk factor for vascular cognitive impairment and is strongly associated with carotid artery stenosis. In normotensive rats, chronic cerebral hypoperfusion induced by bilateral common carotid artery stenosis (BCAS) leads to cognitive impairment that is associated with impaired endothelium-dependent dilation in parenchymal arterioles (PAs). The aim of this study was to assess the effects of BCAS on PA function and structure in stroke-prone spontaneously hypertensive rats, a model of human essential hypertension. Understanding the effects of hypoperfusion on PAs in a hypertensive model could lead to the identification of therapeutic targets for cognitive decline in a model that reflects the at-risk population. We hypothesized that BCAS would impair endothelium-dependent dilation in PAs and induce artery remodeling compared with sham rats. PAs from BCAS rats had endothelial dysfunction, as assessed using pressure myography. Inhibition of nitric oxide and prostaglandin production had no effect on PA dilation in sham or BCAS rats. Surprisingly, inhibition of epoxyeicosatrienoic acid production increased dilation in PAs from BCAS rats but not from sham rats. Similar results were observed in the presence of inhibitors for all three dilatory pathways, suggesting that epoxygenase inhibition may have restored a nitric oxide/prostaglandin-independent dilatory pathway in PAs from BCAS rats. PAs from BCAS rats underwent remodeling with a reduced wall thickness. These data suggest that marked endothelial dysfunction in PAs from stroke-prone spontaneously hypertensive rats with BCAS may be associated with the development of vascular cognitive impairment. NEW & NOTEWORTHY The present study assessed the structure and function of parenchymal arterioles in a model of chronic cerebral hypoperfusion and hypertension, both of which are risk factors for cognitive impairment. We observed that impaired dilation and artery remodeling in parenchymal arterioles and abolished cerebrovascular reserve capacity may mediate cognitive deficits.
