Linked Life Data

2000988

Source:http://linkedlifedata.com/resource/pubmed/id/2000988

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3 Pt 2
pubmed:dateCreated
1991-4-11
pubmed:abstractText
Cardiac hypertrophy and heart failure are common to acromegalic patients who have abnormally high serum growth hormone (GH). While the function of cardiac muscle is clearly affected by chronically elevated GH, the electrical activity of myocytes from hearts with GH-dependent hypertrophy has not been studied. We used adult, female Wistar-Furth rats with induced GH-secreting tumors to study the effect of excessive GH on ion channels of cardiac myocytes. GH-secreting tumors were induced by subcutaneous inoculation of GH3 cells. Eight weeks after inoculation, the rats had doubled their body weight and heart size compared with age-matched controls. There were no differences in either action potential amplitude or resting potential of right ventricular myocytes from control and tumor-bearing rats. However, action potential duration increased significantly in tumor-bearing rats; the time to 50% repolarization was 23 +/- 14 ms (n = 10) compared with 6.6 +/- 1.5 ms (n = 14) in controls. The prolongation of the action potential was mainly due to a decrease in density of a transient outward current (It,o) carried by K+. The normalized conductance for It,o decreased from 0.53 +/- 0.10 nS/pF (n = 25) in controls to 0.33 +/- 0.09 nS/pF (n = 26) in tumor-bearing rats. The decrease in It,o) and increase in heart weight occurred with a similar time course. The increased action potential duration prolongs Ca2+ influx through L-type Ca2+ channels in the tumor-bearing animals; this may be important in cardiovascular adaptation.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0002-9513
pubmed:author
pubmed:issnType
Print
pubmed:volume
260
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
H935-42
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1991
pubmed:articleTitle
Decreased transient outward K+ current in ventricular myocytes from acromegalic rats.
pubmed:affiliation
Department of Physiology and Biophysics, University of Illinois, Urbana-Champaign 61801.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't