Optical projection tomography permits efficient assessment of infarct volume in the murine heart postmyocardial infarction.
Bottom Line: Experimental studies therefore commonly assess injury by histological analysis of sections sampled from the infarcted heart, an approach that is labor intensive, can be subjective, and does not fully assess the extent of injury.Intact, perfusion-fixed, optically cleared hearts, collected from mice 7 days after induction of MI by coronary artery occlusion, were scanned by a tomograph for autofluorescence emission after UV excitation, generating >400 transaxial sections for reconstruction.Tissue processing for OPT did not compromise subsequent immunohistochemical detection of endothelial cell and inflammatory cell markers.
Affiliation: BHF/University Centre for Cardiovascular Science, Queen's Medical Research Institute, University of Edinburgh, Edinburgh, United Kingdom;Show MeSH
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Mentions: To determine the suitability of OPT for the identification of infarcted myocardium, 7 day postinfarct hearts were scanned for visible light transmittance and at two different fluorescent emission wavelengths (Fig. 3). While scanning in the visible (white) light channel, the contrast between viable and infarcted myocardium was sufficient to allow image reconstruction. However, emission from collagen or other fibrotic elements was too bright and widely distributed to permit threshold setting and analysis (Fig. 3, A and D). In both fluorescence emission channels, the viable myocardium was observed to have strong autofluorescence and was clearly delineated from infarct regions. Better resolution in the noninfarcted tissue and optimal discrimination between infarct and healthy myocardium were achieved following excitation at 470 nm (Fig. 3, C and F), and fluorescent emission imaging with excitation at 470 nm was thus adopted for all further investigations.
Affiliation: BHF/University Centre for Cardiovascular Science, Queen's Medical Research Institute, University of Edinburgh, Edinburgh, United Kingdom;