Presence of intracisternal type A particles in normal bone tissue from various mouse strains.

Intracisternal type A particles were detected by electron microscopy in cells of normal trabecular bone tissue from the mouse strains C57BL, NMRI, C3H, 101, and (C3H X 101)F1. The relatively small numbers of particles observed in all five strains were roughly equivalent. About 10% of the bone cell profiles examined in specimens from each animal contained a single particle. The intracisternal type A particles occurred predominantly in osteoblasts and rarely in osteoprogenitor cells and osteocytes. They were not found in osteoclasts.