Regional changes in cerebral blood flow between the upright and supine posture and over 3 days of bed rest.

IF 2.6 4区医学 Q2 PHYSIOLOGY

Experimental Physiology Pub Date : 2025-01-22 DOI:10.1113/EP091820

Carmen Possnig, Kyohei Marume, Gautam Babu, Sylvan L J E Janssen, Christopher M Hearon, Katrin A Dias, Satyam Sarma, Justin S Lawley, Benjamin D Levine

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引用次数: 0

Abstract

A reduction in cerebral blood flow (CBF) has been observed during spaceflight and bed rest. We aimed to examine the magnitude and regional heterogeneity of the decrease in CBF during bed rest compared to posture changes on Earth. Seventeen participants (age, 29 ± 9 years, 7 females) were studied in the upright and supine posture and over 3 days of bed rest. We assessed blood flow via duplex ultrasonography in the internal carotid (ICA) and vertebral arteries (VA), and via transcranial Doppler of the middle cerebral artery (MCAv). Mean arterial pressure (MAP) and end-tidal CO₂ ( $E T_{C O_{2}}$ ) were assessed at all time points. By day 3, total CBF (1078 ± 302 to 853 ± 245 mL min^-1, P < 0.0001) and MCAv (61 ± 15 to 49 ± 12 mL min^-1, P < 0.0001) were decreased compared to the supine posture. CBF values did not fall below the upright posture (all P > 0.05) but were lower than a calculated 24-h mean baseline (P = 0.0132). MAP remained stable (P = 0.971), as did $E T_{C O_{2}}$ (P = 0.0803), while VA blood flow decreased after 24 h and again after 72 h (P = 0.0024). These findings indicate that CBF decreases during short-term bed rest, but not below values observed in the upright posture.

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来源期刊

Experimental Physiology 医学-生理学

CiteScore

5.10

自引率

3.70%

发文量

262

审稿时长

1 months

期刊介绍： Experimental Physiology publishes research papers that report novel insights into homeostatic and adaptive responses in health, as well as those that further our understanding of pathophysiological mechanisms in disease. We encourage papers that embrace the journal’s orientation of translation and integration, including studies of the adaptive responses to exercise, acute and chronic environmental stressors, growth and aging, and diseases where integrative homeostatic mechanisms play a key role in the response to and evolution of the disease process. Examples of such diseases include hypertension, heart failure, hypoxic lung disease, endocrine and neurological disorders. We are also keen to publish research that has a translational aspect or clinical application. Comparative physiology work that can be applied to aid the understanding human physiology is also encouraged. Manuscripts that report the use of bioinformatic, genomic, molecular, proteomic and cellular techniques to provide novel insights into integrative physiological and pathophysiological mechanisms are welcomed.