ISSN:
1540-8191
Source:
Blackwell Publishing Journal Backfiles 1879-2005
Topics:
Medicine
Notes:
Abstract Background: The use of left ventricular (LV) assist devices (LVADs) can improve performance and recovery of failing human hearts. Aim: Following our alpha-adrenergic receptor work, we hypothesized that mechanical unloading in patients with low output syndrome and LV failure would yield similar results with beta-adrenergic receptors (βAR), that being increased numbers and intra-myocytic relocalization. Methods:βAR density and localization were investigated by fluorescence deconvolution microscopy and compared at LVAD insertion and removal in 13 heart failure patients, the patients therefore acting as their own control. βAR densities and distribution were determined in snap frozen sections of human core biopsy left ventricular apical tissue. Samples were probed with tagged CGP 12177 for visualization of βAR and challenged with cold agonists and antagonists. βAR density was measured by two independent methods. Localization of receptors was examined in reconstructed, deconvoluted, stacked section images. Results: There was an increase in βAR density following ventricular unloading in most of the patients, and also significant normalization in the location of the receptors in the myocardium comparing pre- and post-LVAD tissue. Conclusions: These findings suggest that supporting an ailing heart via unloading initiates mechanisms and pathways responsible for myocardial recovery and repair. With appropriate pharmacological support, patients with LVAD might recover to the point where they no longer depend on eventual organ transplantation, and βAR number, type, and distribution in pre-LVAD myocardial tissue, could predict outcome with regard to recovery, repair, and improvement in cardiac function.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1111/j.1540-8191.2005.2004105.x
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