Pages 29-30
The changes in morphology of isolated nuclei nuclei from endothelial cells were investigated before and after exposure to fluid flow. In addition, the Young's modulus of nuclei was determined with pipette aspiration technique. In fluorescence observation, the nuclei in the cells were initially found compressed vertically and the isolated nuclei remained almost rounded shape under static conditions. In contrast, the nuclei before and after isolation showed elongated shape under sheared conditions. These results showed that the compressed nuclei were elongated by fluid flow in the same fashion of cell shape change, and then continued to keep their morphology even after isolation. The Young's modulus of isolated nuclei increased after exposure to fluid flow. Not only an increase in strain state but also remodeling of nucleus structure due to compression and elongation may induce hardening of nuclei.
