{"title":"Chronic hypertension alters the relationship between collateral blood flow cortical cerebral blood flow, and brain tissue oxygenation.","authors":"Ryan D Hunt, Marilyn J Cipolla","doi":"10.1177/0271678X241258569","DOIUrl":null,"url":null,"abstract":"<p><p>This study measured the relationship between pial collateral (leptomeningeal anastomoses, LMA) flow, intraparenchymal cortical cerebral blood flow (cCBF) and brain tissue oxygenation (btO<sub>2</sub>) during acute ischemic stroke to investigate how pial flow translates to downstream cCBF and btO<sub>2</sub> and examined how this relationship is altered in hypertension. Proximal transient middle cerebral artery occlusion (tMCAO) was performed in male Wistar (n = 8/group) and Spontaneously Hypertensive Rats (SHR, n = 8/group). A combination laser Doppler-oxygen probe was placed within the expected cortical peri-infarct in addition to a surface laser doppler probe which measured LMA flow. Phenylephrine (PE) was infused 30 minutes into tMCAO to increase blood pressure (BP) by 30% for 10 minutes and assessed CBF autoregulation. During the initial 30-minute period of tMCAO, btO<sub>2</sub> and cCBF were lower in SHR compared to Wistar rats (btO<sub>2</sub>: 11.5 ± 10.5 vs 17.5 ± 10.8 mmHg and cCBF: -29.7 ± 23.3% vs -17.8 ± 41.9%); however, LMA flow was similar between groups. The relationship between LMA flow, cCBF and btO<sub>2</sub> were interdependent in Wistar rats. However, this relationship was disrupted in SHR rats and partially restored by induced hypertension. This study provides evidence that cCBF and btO<sub>2</sub> were diminished during tMCAO in chronic hypertension, and that induced hypertension was beneficial regardless of hypertensive status.</p>","PeriodicalId":15325,"journal":{"name":"Journal of Cerebral Blood Flow and Metabolism","volume":null,"pages":null},"PeriodicalIF":4.9000,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11542142/pdf/","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Cerebral Blood Flow and Metabolism","FirstCategoryId":"3","ListUrlMain":"https://doi.org/10.1177/0271678X241258569","RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"2024/5/28 0:00:00","PubModel":"Epub","JCR":"Q1","JCRName":"ENDOCRINOLOGY & METABOLISM","Score":null,"Total":0}
引用次数: 0
Abstract
This study measured the relationship between pial collateral (leptomeningeal anastomoses, LMA) flow, intraparenchymal cortical cerebral blood flow (cCBF) and brain tissue oxygenation (btO2) during acute ischemic stroke to investigate how pial flow translates to downstream cCBF and btO2 and examined how this relationship is altered in hypertension. Proximal transient middle cerebral artery occlusion (tMCAO) was performed in male Wistar (n = 8/group) and Spontaneously Hypertensive Rats (SHR, n = 8/group). A combination laser Doppler-oxygen probe was placed within the expected cortical peri-infarct in addition to a surface laser doppler probe which measured LMA flow. Phenylephrine (PE) was infused 30 minutes into tMCAO to increase blood pressure (BP) by 30% for 10 minutes and assessed CBF autoregulation. During the initial 30-minute period of tMCAO, btO2 and cCBF were lower in SHR compared to Wistar rats (btO2: 11.5 ± 10.5 vs 17.5 ± 10.8 mmHg and cCBF: -29.7 ± 23.3% vs -17.8 ± 41.9%); however, LMA flow was similar between groups. The relationship between LMA flow, cCBF and btO2 were interdependent in Wistar rats. However, this relationship was disrupted in SHR rats and partially restored by induced hypertension. This study provides evidence that cCBF and btO2 were diminished during tMCAO in chronic hypertension, and that induced hypertension was beneficial regardless of hypertensive status.
期刊介绍:
JCBFM is the official journal of the International Society for Cerebral Blood Flow & Metabolism, which is committed to publishing high quality, independently peer-reviewed research and review material. JCBFM stands at the interface between basic and clinical neurovascular research, and features timely and relevant research highlighting experimental, theoretical, and clinical aspects of brain circulation, metabolism and imaging. The journal is relevant to any physician or scientist with an interest in brain function, cerebrovascular disease, cerebral vascular regulation and brain metabolism, including neurologists, neurochemists, physiologists, pharmacologists, anesthesiologists, neuroradiologists, neurosurgeons, neuropathologists and neuroscientists.