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Titre du document / Document title

Hypoxia, hypercapnia, and hypertension : their effects on pulsatile cerebral blood flow

Auteur(s) / Author(s)

CURRAN-EVERETT D. ; YIMING ZHANG ; JONES R. H. ; JONES M. D. ;

Affiliation(s) du ou des auteurs / Author(s) Affiliation(s)

Univ. Colorado health sci. cent., dep. pediatrics and preventive medicine biometrics, Denver CO 80262, ETATS-UNIS

Résumé / Abstract

Curran-Everett, Douglas, Yiming Zhang, Richard H. Jones, and M. Douglas Jones, Jr. Hypoxia, hypercapnia, and hypertension : their effects on pulsatile cerebral blood flow. J. Appl. Physiol. 79(3) : 870-878, 1995.-Pulsatile cerebral blood flow reflects characteristics of arterial blood pressure as well as the structure and mechanical properties of the cerebrovascular network. Although the effects of changes in systemic blood gases and blood pressure on mean cerebral flow are established, their effects on pulsatile cerebral blood flow are unknown. These studies assessed the effects of hypoxia-hypercapnia (combined ; both arterial PO2 and PCO2 ∼55 Torr) and acute hypertension (+30-35 mmHg by aortic occlusion) on pulsatile cerebral blood flow in ketamine-anesthetized rabbits. We characterized the relationship between pulsatile systemic blood pressure (Millar catheter) and cerebral cortical capillary blood-flow (laser-Doppler) by calculating the transfer function, a frequency-domain expression that relates amplitudes and phase angles of flow output to those of the pressure input. During hypoxia-hypercapnia, mean flow increased 17% (P < 0.001), but the amplitude and contour of pulsatile cortical blood flow were unchanged (P > 0.10). Although aortic occlusion, during hypoxia-hypercapnia as well as during normoxia-normocapnia, increased systemic pulse pressure by 40%, the amplitude of cortical flow pulsations was unaffected. Changes in dynamic properties of the cerebral vasculature (P < 0.0001 by analysis of the transfer function) minimized alterations in pulsatile cortical blood flow and thus intrabeat vessel wall stress during acute hypertension; on the basis of analysis of an electrical analogue, we propose that these changes reflect alterations in both resistance and compliance.

Revue / Journal Title

Journal of applied physiology    ISSN  8750-7587   CODEN JAPHEV 

Source / Source

1995, vol. 79, no3, pp. 870-878 (29 ref.)

Langue / Language

Anglais

Editeur / Publisher

American Physiological Society, Bethesda, MD, ETATS-UNIS  (1985) (Revue)

Mots-clés anglais / English Keywords

Hypoxia

;

Hypercapnia

;

Hypertension

;

Regional blood flow

;

Pulsatile

;

Brain (vertebrata)

;

Microcirculation

;

Transfer function

;

Fourier transformation

;

Frequency domain method

;

Rabbit

;

Oxygen

;

Environmental factor

;

Carbon dioxide

;

Cardiovascular disease

;

Hemodynamics

;

Central nervous system

;

Lagomorpha

;

Mammalia

;

Vertebrata

;

Mots-clés français / French Keywords

Hypoxie

;

Hypercapnie

;

Hypertension artérielle

;

Débit sanguin régional

;

Pulsatile

;

Encéphale

;

Microcirculation

;

Fonction transfert

;

Transformation Fourier

;

Méthode domaine fréquence

;

Lapin

;

Oxygène

;

Facteur milieu

;

Carbone dioxyde

;

Appareil circulatoire pathologie

;

Hémodynamique

;

Système nerveux central

;

Lagomorpha

;

Mammalia

;

Vertebrata

;

Mots-clés espagnols / Spanish Keywords

Hipoxia

;

Hipercapnia

;

Hipertensión arterial

;

Flujo sanguíneo regional

;

Pulsátil

;

Encéfalo

;

Microcirculación

;

Función traspaso

;

Transformación Fourier

;

Método dominio frecuencia

;

Conejo

;

Oxígeno

;

Factor medio

;

Carbono dióxido

;

Aparato circulatorio patología

;

Hemodinámica

;

Sistema nervioso central

;

Lagomorpha

;

Mammalia

;

Vertebrata

;

Localisation / Location

INIST-CNRS, Cote INIST : 5400, 35400005466801.0280

Nº notice refdoc (ud4) : 3682130



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