Mitochondrial function and cerebral blood flow responses under unilateral carotid occlusion in rats

Abstract

Introduction: Unilateral Carotid Occlusion (UCO) serves as a model of partial cerebral ischemia which mimics clinical situations such as stenosis or atherosclerosis. UCO has known to have slight and merely short-term effects on cerebral hemodynamic and metabolic functions. The aim of this study was to test the effects of UCO compared to bilateral carotid occlusion (BCO) on the responses of the brain to spreading depression (SD). Methods: Rats were monitored up to 24 hours after UCO and BCO using a Multi-Site - Multi-Parametric (MSMP) system, which evaluates mitochondrial function using the NADH fluorometry and CBF using laser Doppler flowmetry. The induction of SD and the exposure to short anoxia served as tools to investigate the effects of UCO and BCO on the brain. Results: UCO and BCO led to a short lasting decrease in CBF and an increase in NADH. During SD waves and short anoxia a hyperemic response occurred, which decreased 24 hours following UCO in the hemisphere ipsilateral to the occluded artery and increased in the contralateral hemisphere. The hyperemic response decreased in both hemispheres 24 hours following BCO. NADH levels during SD waves increased in the hemisphere ipsilateral to the occluded artery following UCO and in both hemispheres following BCO, but remained similar to control levels during short anoxia. Conclusions: UCO leads to long term alterations in cerebral blood supply, which may be detected 24 hours following such occlusion. These changes are minor compared to the effect of BCO and have minimal influence on mitochondrial function.