Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
6
pubmed:dateCreated
1982-5-27
pubmed:abstractText
The effects of clonidine HCI were compared with those of 5-HTP on transmission through two spinal sympathetic pathways, segmental spinal reflex pathways and descending intraspinal excitatory pathways, in unanesthetized spinal cats. Evoked sympathetic discharges were recorded from upper thoracic preganglionic rami. Clonidine (5-50 microgram/kg) produced a parallel, dose-dependent depression of transmission through each pathway. The intraspinal pathway was five time more sensitive than the spinal reflex pathway (ED50's, 6 and 30 microgram/kg), and the spinal reflex pathway could not be depressed by more than 60% even by higher doses. In contrast, 5-HTP was more effective in depressing the spinal reflex than the intraspinal pathway (ED50's 32 and 44 mg/kg), and both pathways could be depressed completely. Small doses of tolazoline or yohimbine rapidly antagonized the effects of clonidine but not 5-HTP. Clonidine and 5-HTP appear to depress the excitability of sympathetic preganglionic neurons by activating alpha2- and 5-HT receptors, respectively. Each mechanism may contribute independently to regulation of the sympathetic outflow.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:issn
0148-3927
pubmed:author
pubmed:issnType
Print
pubmed:volume
3
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1151-63
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1981
pubmed:articleTitle
Contrasting effects of clonidine and 5-hydroxytryptophan on spinal sympathetic pathways.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, U.S. Gov't, P.H.S.