Transmural Differences in Mechanical Properties of Isolated Subendocardial and Subepicardial Cardiomyocytes.

We studied the differences in twitch force of subendocardial and subepicardial cardiomyocytes isolated from mouse left ventricular wall at different preloads using an original single cell stretch method recently developed by us. Then, we used our mathematical models of subendocardial and subepicardial cells to predict underlying cellular mechanisms. Transmural differences in the amplitudes of active tension of subendocardial and subepicardial cardiomyocytes were revealed that could be related to the differences in cooperative end-to-end interaction between the neighboring regulatory units of the thin filament.