Morphometry of bone cell nuclei and their location relative to bone surfaces.

The shapes and locations of lining cells, osteoblasts and osteoprogenitors in sections of rat bone have been quantified by means of a digitiser. The nuclei of all three types of cells can be characterised by oblate spheroids (ellipsoids of revolution). The axis dimensions, their relative variations and the correlation between these parameters have been determined by computer simulation. The nuclear volume of progenitors (288 microns) is more than twice the volume of osteblasts and lining cells (127 microns and 113 microns, respectively). The true mean perpendicular distances of nuclei are 3.1 microns, 5.7 microns and 7.7 microns for lining cells, osteoblasts and progenitors, respectively. The probability densities for true perpendicular distances have been calculated and analytical expressions are given that formally characterise these densities.