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rdf:type | |
lifeskim:mentions | |
pubmed:dateCreated |
1991-2-11
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pubmed:abstractText |
Activity in central sympathetic pathways can be modified by stimulating central alpha 2-adrenoceptors, e.g., with clonidine, or, more recently, by stimulating central 5-hydroxytryptamine (5-HT1A) receptors. Stimulation of 5-HT1A receptors causes central sympathoinhibition and an increase in cardiac vagal drive, which results in a profound fall in blood pressure. However, the central sympathoinhibition observed with 5-HT1A agonists such as 8-OH-DPAT [8-hydroxy-2-(di-n-propylamino)tetralin] is not uniform for all regional sympathetic outflows, renal outflow being the most sensitive. The classical centrally acting antihypertensive drugs, the alpha 2-adrenoceptor agonists, also cause differential sympathoinhibition, but cardiac rather than renal nerve activity is the most sensitive. Now, if a 5-HT1A agonist is combined with an alpha 1-adrenoceptor antagonist, e.g., urapidil, then uniform central sympathoinhibition is observed. 5-HT1A agonists also differ from alpha 2-adrenoceptor agonists in that they increase central vagal drive. Further, 5-HT-containing boutons have been shown to make synaptic contact with cardiac vagal motoneurons (CVMs), and there is also a high density of 5-HT1A binding in the brain nuclei containing these CVMs. This suggests that there is an excitatory 5-HT-containing pathway that innervates CVMs and involves the activation of 5-HT1A receptors. In this respect, cardiopulmonary afferent fiber activation of CVMs is blocked by central administration of 5-HT1A receptor antagonists. In conclusion, 5-HT1A receptors are important in the patterning of sympathetic outflow by central cardiovascular pathways and are involved in the central control of parasympathetic outflow, at least to the heart.
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pubmed:language |
eng
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pubmed:journal | |
pubmed:citationSubset |
IM
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pubmed:chemical | |
pubmed:status |
MEDLINE
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pubmed:issn |
0160-2446
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pubmed:author | |
pubmed:issnType |
Print
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pubmed:volume |
15 Suppl 7
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
S75-85
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pubmed:dateRevised |
2006-11-15
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pubmed:meshHeading | |
pubmed:year |
1990
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pubmed:articleTitle |
Influence of 5-HT1A receptor agonists on sympathetic and parasympathetic nerve activity.
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pubmed:affiliation |
Academic Department of Pharmacology, Royal Free Hospital School of Medicine, Hampstead, London, England.
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pubmed:publicationType |
Journal Article,
Review,
Research Support, Non-U.S. Gov't
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