Switch to
Predicate | Object |
---|---|
rdf:type | |
lifeskim:mentions | |
pubmed:issue |
14
|
pubmed:dateCreated |
1991-5-2
|
pubmed:abstractText |
The purpose of this study was to evaluate the effects of vascular and central alpha-adrenoceptor blockade on cerebral blood flow (CBF) and utilization of brain arteriolar and capillary reserve in conscious rats during normoxia and hypoxia (8% O2 in N2). Animals were divided into three groups and administered either saline, N-methyl chlorpromazine (does not cross the blood-brain barrier), or phenoxybenzamine (crosses the blood-brain barrier) in equipotent doses. Neither agent affected regional CBF and the utilization of brain microvascular reserve during normoxia. CBF increased from 70.9 +/- 2.9 (SEM) ml/min/100 g in the control normoxic group to 123.8 +/- 4.2 ml/min/100 g in control hypoxic animals. In control, hypoxic flow to pons and medulla of the brain was higher than to cortex, hypothalamus or thalamus. The percent of arterioles/mm2 perfused increased from 49.6 +/- 2.0% during control normoxia to 65.6 +/- 3.0% during control hypoxia. The percentage of capillaries/mm2 perfused changed similarly. Hypoxic CBF was increased similarly after administration of N-methyl chlorpromazine or phenoxybenzamine. Administration of N-methyl chlorpromazine or phenoxybenzamine eliminated regional differences in hypoxic CBF and the utilization of arterioles, and did not affect capillary response. There was no difference between the effect of N-methyl chlorpromazine and phenoxybenzamine on cerebral microvascular and blood flow responses to hypoxia. It was concluded that peripheral alpha-adrenoceptors affect the distribution of regional microvascular and blood flow responses to hypoxia, and central alpha-adrenoceptors probably do not participate in this effect.
|
pubmed:grant | |
pubmed:language |
eng
|
pubmed:journal | |
pubmed:citationSubset |
IM
|
pubmed:chemical | |
pubmed:status |
MEDLINE
|
pubmed:issn |
0024-3205
|
pubmed:author | |
pubmed:issnType |
Print
|
pubmed:volume |
48
|
pubmed:owner |
NLM
|
pubmed:authorsComplete |
Y
|
pubmed:pagination |
1351-63
|
pubmed:dateRevised |
2007-11-15
|
pubmed:meshHeading |
pubmed-meshheading:1672555-Adrenergic alpha-Antagonists,
pubmed-meshheading:1672555-Animals,
pubmed-meshheading:1672555-Anoxia,
pubmed-meshheading:1672555-Brain,
pubmed-meshheading:1672555-Hemodynamics,
pubmed-meshheading:1672555-Male,
pubmed-meshheading:1672555-Microcirculation,
pubmed-meshheading:1672555-Rats,
pubmed-meshheading:1672555-Receptors, Adrenergic, alpha
|
pubmed:year |
1991
|
pubmed:articleTitle |
Effect of peripheral and central alpha-adrenoceptor blockade on cerebral microvascular and blood flow responses to hypoxia.
|
pubmed:affiliation |
Department of Physiology and Biophysics University of Medicine and Dentistry of New Jersey Robert Wood Johnson Medical School, Piscataway 08854-5635.
|
pubmed:publicationType |
Journal Article,
Research Support, U.S. Gov't, P.H.S.
|