Linked Life Data

8430864

Source:http://linkedlifedata.com/resource/pubmed/id/8430864

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1 Pt 2
pubmed:dateCreated
1993-3-5
pubmed:abstractText
The alpha 1-adrenergic modulation of the transient outward potassium current (I(t)) was studied in single cardiac myocytes obtained from normal (euthyroid) and hyperthyroid rabbits. Rabbits were made hyperthyroid by four or five daily intraperitoneal injections of 0.4 mg/kg body wt thyroxine. Currents were recorded using the whole cell, suction-electrode, voltage-clamp method. It was found that the alpha-adrenergic agonist methoxamine attenuates I(t) in rabbit ventricular cells, as reported earlier for atrial cells. This attenuation is significantly reduced in the hyperthyroid state. For example, 0.2 mM reduces I(t) magnitude (at +20 mV) by close to 40% in euthyroid cells and by only 20% in the hyperthyroid cells. Half-maximal effective concentration values (extrapolated) are close to 0.4 mM in normal and 1 mM in hyperthyroid cells. Preliminary results show similar effects in atrial cells as well. These results may be related to a decrease in the density of membrane alpha-adrenergic receptors in hyperthyroid conditions, or to the induction of a new class of I(t) channels that is less sensitive to alpha-agonists.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0002-9513
pubmed:author
pubmed:issnType
Print
pubmed:volume
264
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
H74-7
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1993
pubmed:articleTitle
Alpha-adrenergic modulation of transient outward current in hyperthyroid rabbit myocytes.
pubmed:affiliation
Department of Medical Physiology, University of Calgary, Alberta, Canada.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't