Three-dimensional visualization of coronary microvasculature in rats with myocardial infarction

Abstract Background Assessment of the coronary microcirculation remains challenging. Objective we explored the feasibility of evaluating the coronary microvasculature in rats with myocardial infarction (MI) using a three-dimensional visualization technique. Methods Animals were divided into the sham operation group (S), MI 45 min group (M45), and MI 180 min group (M180). Opened microvessels were labelled with the fluorescent dye DiI (1, 1′-dioctadecyl-3, 3, 3′3′-tetramethylindo carbocyanine perchlorate) using a heart perfusion method. The microvascular distribution and opening status were observed under laser scanning confocal microscopy, which was adjusted to facilitate evaluation of subjects around 6 to 20 μm. Results Microvascular vessels (6-20 μm) were successfully labelled by DiI. Intact and clear three-dimensional microvascular structures were observed in myocardium of sham rats and remote non-infarct myocardial tissue of MI rats, while there was almost no microvascular structure in the infarct area of the M45 group, and only a small amount of microvascular visualization was visualized in the infarct area of the M180 group. The microvascular area and microvascular density in M45 group and M180 group in the infarct border zone were significantly lower than corresponding area in S group. Conclusion Three-dimensional visualization of opened coronary microvascular vessels is feasible in DiI-labelled myocardium in this rat MI model. This novel technique might be useful for defining the underlying mechanisms of coronary microvascular diseases and observe the efficacy of various therapy strategies on coronary microvessels.