Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
1987-9-25
pubmed:abstractText
The effects of 3 phosphodiesterase inhibitors, aminophylline, isobutylmethylxanthine (IBMX), and RO 20-1724, were tested on descending intraspinal and spinal reflex transmission to sympathetic preganglionic neurons in unanesthetized spinal cats. Sympathetic discharges, recorded from upper thoracic preganglionic white rami, were evoked by stimulation (0.1 Hz) of descending excitatory pathways in the cervical dorsolateral funiculus (intraspinal) or of adjacent intercostal nerves (spinal reflex). Each phosphodiesterase rapidly and markedly enhanced transmission through intraspinal pathways but only slowly and modestly enhanced transmission through spinal reflex pathways. Pretreatment with a methyltyrosine-reserpine combination, chlorpromazine, or prazosin markedly restricted the enhancement of intraspinal transmission by IBMX to levels typically produced on spinal reflex pathways. Clonidine markedly depressed transmission through both pathways and prevented enhancement by the phosphodiesterase inhibitors. Yohimbine or tolazoline antagonized the depressant effects of clonidine and restored the ability of the phosphodiesterase inhibitors to enhance transmission. Somatic spinal reflexes were not affected by the phosphodiesterase inhibitors. The results suggest that descending norepinephrine pathways to sympathetic preganglionic neurons activate adenylate cyclase to generate cyclic AMP which increases neuronal excitability, possibly by phosphorylating membrane proteins. Clonidine appears to depress neuronal excitability by inhibiting adenylate cyclase through activation of alpha 2-adrenergic receptors.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
0165-1838
pubmed:author
pubmed:issnType
Print
pubmed:volume
19
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
199-209
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1987
pubmed:articleTitle
Enhancement of central transmission to sympathetic preganglionic neurons by phosphodiesterase inhibitors and its prevention by clonidine.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't