Abstract 20088: Non-Uniform Distribution of Adrenergic-Derived Cells in Left Ventricular Myocardium: Implications for Tako-Tsubo Syndrome
To identify adrenergic-derived cells in the adult mouse heart, we performed genetic fate-mapping experiments in which the Cre-recombinase gene was inserted into the phenylethanolamine-n-methyltransferase (Pnmt) gene locus, and then cross-mated with the homozygous Rosa26 reporter mouse strain. This mating resulted in offspring that produced βGAL in cells of an adrenergic lineage. Blue XGAL+ staining revealed adrenergic-derived cells throughout the adult mouse heart, though the distribution of XGAL+ cells was predominately in the left atrium (LA) and ventricle (LV). The XGAL+ staining in the left heart accounted for 89% of the total XGAL+ staining. The LV free wall showed intermittent staining, extending from the apex to the base of the heart, and included heavy staining of the anterior papillary muscle, along its perimeter. The right atrium (RA) and ventricle (RV) collectively showed significantly less XGAL+ staining when compared to the LA and LV (P=0.001). Three-dimensional computer-aided reconstruction of XGAL+ staining revealed distribution throughout the left atrium and ventricle. In particular, adrenergic-derived cells were arranged in a non-random pattern within the left ventricle such that the distribution was within a specific segment of the helical ventricular myocardial band (HVMB), with concentrations of them appearing in the mid and apical regions. This distinctive left-sided localization of the adrenergic-derived cells suggests that they may play a role in Tako-Tsubo Syndrome, a stress-induced cardiomyopathy characterized in part by hypokinesis of mid and apical regions of left ventricular muscle.
- © 2010 by American Heart Association, Inc.