effect of hypercapnia on a blood-brain barrier mechanism in foetal and new-born sheep
1. The effect of marked hypercapnia (arterial PCO2 100 mmHg), nonrespiratory acidosis (pH 6-95-7-15) or hypoxia (arterial PO2 10-15 mmHg) upon penetration of labelled sucrose from blood into brain and c.s.f. has been investigated in exteriorized foetal sheep and new-born lambs. 2. In hypercapnia the...
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Published in | The Journal of physiology Vol. 255; no. 3; pp. 701 - 714 |
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Main Authors | , , , |
Format | Journal Article |
Language | English |
Published |
England
The Physiological Society
01.03.1976
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Subjects | |
Online Access | Get full text |
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Summary: | 1. The effect of marked hypercapnia (arterial PCO2 100 mmHg), nonrespiratory acidosis (pH 6-95-7-15) or hypoxia (arterial
PO2 10-15 mmHg) upon penetration of labelled sucrose from blood into brain and c.s.f. has been investigated in exteriorized
foetal sheep and new-born lambs. 2. In hypercapnia there was a consistent increase in c.s.f./plasma sucrose ratio after 90
min I.V. sucrose to four to five times control. Brain/plasma sucrose ratios were more variable. Usually there was an increase
(up to three-and-a-half-times control); sometimes there was no change or even a decrease. The effect of hypercapnia on sucrose
penetration was reversible. 3. Hypercapnia reduced c.s.f. secretion rate to approximately half the control value. Hypercapnia
also caused a decrease in brain extracellular space. 4. Non-respiratory acidosis did not affect sucrose penetration. Hypoxia
caused a decrease in brain/plasma sucrose ratio. 5. It is concluded that hypercapnia can cuase an increase in cerebral vascular
permeability to sucrose in foetal and new-born sheep. Some possible mechanisms are discussed. |
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Bibliography: | ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
ISSN: | 0022-3751 1469-7793 |
DOI: | 10.1113/jphysiol.1976.sp011304 |