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Increased arrhythmogenesis and expression of left ventricular pS368‐Connexin43 following acute myocardial ischemia (AMI) in female ovariectomized rats
Author(s) -
Jarrett Erica,
Firkins Rachel M.,
Henry Matthew K.,
Moffitt Julia A.
Publication year - 2013
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.27.1_supplement.928.13
Subject(s) - ovariectomized rat , medicine , cardiology , myocardial infarction , phosphorylation , connexin , estrogen , endocrinology , ligation , gap junction , chemistry , intracellular , biochemistry
Estrogen has been previously shown to be protective against ventricular arrhythmias following myocardial infarction possibly through changes in connexin 43 (Cx43) expression and phosphorylation. Phosphorylation of Cx43 at S368 is induced with AMI, suggesting that phosphorylation at this site plays a role in arrhythmogenesis. The goal of the current study was to determine if there is a direct correspondence between phosphorylation of left ventricular (LV)‐Cx43 at S368 and the arrhythmogenic response to AMI, and to further examine if this effect is augmented following loss of estrogen. Anesthetized, ventilated female ovariectomized (n=3) and intact (n=3) Sprague‐Dawley rats were subjected to 20‐minutes of AMI produced through ligation of the left coronary artery. The arrhythmic burden in response to AMI was measured using a standard lead II ECG, and quantified through an established scoring method. Total LV‐Cx43 expression and pS368‐Cx43 expression were measured through standard Western blotting techniques. Ovariectomized animals had a greater arrhythmic burden versus intact animals following AMI. Correspondingly, ovariectomized animals also had an increase in the pS368‐Cx43/Total Cx43 ratio. When data were further examined using a linear regression analysis, results show a direct positive correlation between the level of pS368‐Cx43 expression and arrhythmic burden (R 2 = 0.94). IOER‐3726.