Linked Life Data

16339825

Source:http://linkedlifedata.com/resource/pubmed/id/16339825

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5
pubmed:dateCreated
2006-4-10
pubmed:abstractText
The autocrine modulation of cardiac K(+) currents was compared in ventricular and atrial cells (V and A cells, respectively) from Type 1 diabetic rats. K(+) currents were measured by using whole cell voltage clamp. ANG II was measured by ELISA and immunofluorescent labeling. Oxidative stress was assessed by immunofluorescent labeling with dihydroethidium, a measure of superoxide ions. In V cells, K(+) currents are attenuated after activation of the renin-angiotensin system (RAS) and the resulting ANG II-mediated oxidative stress. In striking contrast, these currents are not attenuated in A cells. Inhibition of the angiotensin-converting enzyme (ACE) also has no effect, in contrast to current augmentation in V cells. ANG II levels are enhanced in V, but not in A, cells. However, the high basal ANG II levels in A cells suggest that in these cells, ANG II-mediated pathways are suppressed, rather than ANG II formation. Concordantly, superoxide ion levels are lower in diabetic A than in V cells. Several findings indicate that high atrial natriuretic peptide (ANP) levels in A cells inhibit RAS activation. In male diabetic V cells, in vitro ANP (300 nM-1 muM, >5 h) decreases oxidative stress and augments K(+) currents, but not when excess ANG II is present. ANP has no effect on ventricular K(+) currents when the RAS is not activated, as in control males, in diabetic males treated with ACE inhibitor and in diabetic females. In conclusion, the modulation of K(+) currents and oxidative stress is significantly different in A and V cells in diabetic rat hearts. The evidence suggests that this is largely due to inhibition of RAS activation and/or action by ANP in A cells. These results may underlie chamber-specific arrhythmogenic mechanisms.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0363-6135
pubmed:author
pubmed:issnType
Print
pubmed:volume
290
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
H1879-88
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2006
pubmed:articleTitle
Differential autocrine modulation of atrial and ventricular potassium currents and of oxidative stress in diabetic rats.
pubmed:affiliation
Department of Physiology and Biophysics, Health Sciences Centre, University of Calgary, Alberta, Canada T2N 4N1. shimoni@ucalgary.ca
pubmed:publicationType
Journal Article, Comparative Study