Oxygen delivery at high blood viscosity and decreased arterial oxygen content to brains of conscious rats

• Verfasst von: Rebel, Annette [VerfasserIn]
• Verfasst von: Lenz, Christian [VerfasserIn]
• Verfasst von: Krieter, Heinrich [VerfasserIn]
• Verfasst von: Waschke, Klaus F. [VerfasserIn]
• Verfasst von: Ackern, Klaus van [VerfasserIn]
• Verfasst von: Kuschinsky, Wolfgang [VerfasserIn]
• Titel: Oxygen delivery at high blood viscosity and decreased arterial oxygen content to brains of conscious rats
• Verf.angabe: A. Rebel, C. Lenz, H. Krieter, K. F. Waschke, K. Van Ackern, W. Kuschinsky
• E-Jahr: 2001
• Jahr: [2001]
• Umfang: 7 S.
• Illustrationen: Diagramme
• Fussnoten: Gesehen am 19.05.2021
• Titel Quelle: Enthalten in: American journal of physiology. Heart and circulatory physiology
• Ort Quelle: Bethesda, Md. : American Physiological Society, 1977
• Jahr Quelle: 2001
• Band/Heft Quelle: 280(2001,6), Seite H2591-H2597
• ISSN Quelle: 1522-1539
• DOI: doi:10.1152/ajpheart.2001.280.6.H2591
• Datenträger: Online-Ressource
• Sprache: eng
• K10plus-PPN: 1758159456

Abstract

We addressed the question to which extent cerebral blood flow (CBF) is maintained when, in addition to a high blood viscosity (Bvis) arterial oxygen content (CaO2) is gradually decreased. CaO2 was decreased by hemodilution to hematocrits (Hct) of 30, 22, 19, and 15% in two groups. One group received blood replacement (BR) only and served as the control. The second group received an additional high viscosity solution of polyvinylpyrrolidone (BR/PVP). Bvis was reduced in the BR group and was doubled in the BR/PVP. Despite different Bvis, CBF did not differ between BR and BR/PVP rats at Hct values of 30 and 22%, indicating a complete vascular compensation of the increased Bvis at decreased CaO2. At an Hct of 19%, local cerebral blood flow (LCBF) in some brain structures was lower in BR/PVP rats than in BR rats. At the lowest Hct of 15%, LCBF of 15 brain structures and mean CBF were reduced in BR/PVP. The resulting decrease in cerebral oxygen delivery in the BR/PVP group indicates a global loss of vascular compensation. We concluded that vasodilating mechanisms compensated for Bvis increases thereby maintaining constant cerebral oxygen delivery. Compensatory mechanisms were exhausted at a Hct of 19% and lower as indicated by the reduction of CBF and cerebral oxygen delivery.