Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1981-8-27
pubmed:abstractText
This study was performed to examine effects of increased intracranial pressure on cerebral blood flow (CBF) and to determine if sympathetic nerves modulate this response. Intracranial pressure was raised by infusion of artificial cerebrospinal fluid into a lateral ventricle of rabbits. Increases in intracranial pressure were similar in the lateral ventricles and cisterna magna. Graded increases in intracranial pressure from base line of 7 to 96 mmHg produced graded reductions in CBF (measured with microspheres). Reductions in blood flow were heterogeneous: elevation of intracranial pressure from 7 +/- 1 to 46 +/- 3 (SE) mmHg reduced blood flow to the cerebrum by 33 +/- 5% and blood flow to the medulla by only 5 +/- 2% (P less than 0.05). Reduction of intracranial pressure to normal levels produced marked reactive hyperemia in all areas of the brain. Although sympathetic nerve traffic increased fivefold during intracranial hypertension, superior cervical ganglionectomy did not affect CBF. In other experiments, electrical stimulation of sympathetic nerves at 4 Hz reduced blood flow to skeletal muscle by 80% but did not affect CBF; stimulation at 15 Hz produced a modest reduction in CBF. We conclude that 1) during increases in intracranial pressure, blood flow is better preserved to the medulla than to the cerebrum despite similar intracranial pressure in the two areas and 2) intense reflex activation of sympathetic nerves during intracranial hypertension does not affect CBF.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
0002-9513
pubmed:author
pubmed:issnType
Print
pubmed:volume
241
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
H78-84
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed:year
1981
pubmed:articleTitle
Cerebral blood flow during elevation of intracranial pressure: role of sympathetic nerves.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, U.S. Gov't, Non-P.H.S.