The three-dimensional structure of vascular smooth muscle cells: a confocal laser microscopic study of rabbit mesenteric arterioles

Abstract

The cross-sectional shapes of arterioles were not circular but elliptical. The aspect ratio (major to minor axis) of the best-fitting ellipse was in the range from 0.3 to 0.7 for 28 arterioles (diameters: 10-30 μm). On the 3D image of VSMCs, the cell width ranged from 2.2 to 4.5 μm. The cells were classified into round and spindle types. The cell width of round shape was significantly larger than that of spindle shape. The VSMCs appeared to arrange circumferentially and tightly along the cross-section along the axis of vessel. The mean length of single VSMCs was approximately 1.2 times of the circumferential length of the arteriole. This cellular arrangement may have influence on the distribution of mechanical stress by VSMC-induced myogenic force.