Nano-imaging of the beating mouse heart in vivo: Importance of sarcomere dynamics, as opposed to sarcomere length per se, in the regulation of cardiac function

摘要: Sarcomeric contraction in cardiomyocytes serves as the basis for heart’s pump functions mammals. Although it plays a critical role circulatory system, myocardial sarcomere length (SL) change has not been directly measured vivo under physiological conditions because of technical difficulties. In this study, we developed high speed (100–frames per second), resolution (20-nm) imaging system sarcomeres living mice. Using conducted three-dimensional analysis dynamics left ventricular myocytes during cardiac cycle, simultaneously with electrocardiogram and pressure measurements. We found that (a) working range SL was on shorter end resting distribution, (b) ventricular–developed positively correlated between diastole systole. The present findings provide first direct evidence tight coupling physiology heart.