Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
6
pubmed:dateCreated
1998-7-1
pubmed:abstractText
Little is known of the factors that regulate CBF in sleep. We therefore studied 10 lambs to assess the vasodilatory processes that underlie cerebral autoregulation during sleep. Lambs, instrumented to measure CBF (flow probe on the superior sagittal sinus), sleep state, and cerebral perfusion pressure (CPP), were rapidly made hypotensive by inflating a cuff around the brachiocephalic artery to reduce CPP to 30 mm Hg in each state. During control periods, cerebral vascular resistance (CVR in mm Hg/mL/min) was lower in active sleep (2.8 +/- 0.3, mean +/- SD, P < or = 0.001) than in wakefulness (3.9 +/- 0.6) and quiet sleep (4.3 +/- 0.6). The CVR decreased promptly in each state as CPP was lowered. The time (seconds) required for maximal cerebral vasodilation to occur was longer in active sleep (35 +/- 11) than in quiet sleep (20 +/- 6, P < or = 0.001) and wakefulness (27 +/- 11, P < or = 0.05). The CVR decreased less in active sleep (0.6 +/- 0.3, P < or = 0.001) than in quiet sleep (1.5 +/- 0.3), although the changes in CPP induced with brachiocephalic occlusion were equal in each state. In conclusion, our studies provide the first evidence that the vasoactive mechanisms that underlie autoregulation of the cerebral circulation function during sleep. Moreover, our data reveal that the speed and the magnitude of the vasodilatory reserves available for autoregulation are significantly less in active sleep than in quiet sleep.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
0271-678X
pubmed:author
pubmed:issnType
Print
pubmed:volume
18
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
639-45
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1998
pubmed:articleTitle
Cerebral circulation in sleep: vasodilatory response to cerebral hypotension.
pubmed:affiliation
Centre for Baby Health Research, Monash University, Clayton, Victoria, Australia.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't