Studies on cell lineage of metaphyseal bone in repleted scorbutic guinea pigs.

Young weanling guinea piglets were placed on a diet deficient only in vitamin C. When they reached a state of severe scorbutus, they were given vitamin C and the morphological differentiation of various mesenchymal cells in the proximal end of the tibia was followed over 7 days. The altering metaphyseal cellular pattern is recorded descriptively as well as quantitatively. Levels of mesenchymal cells, preosteoblasts, osteoblasts, and osteocytes remained relatively steady for 24 h. However, by 48 h there was a precipitous decline of mesenchymal cells with a concomitant rise in recognizable osteogenic cells; this change continued until the 7th day of repletion. At this time, with the exception of the preosteoblasts, the cellular population had returned to about the level in the control animals. Osteoclastic and endothelial cellular movements fluctuated widely during the period of repletion under examination. These results support the concept of separate lines of differentiation for osteoclasts and osteoblasts in the postnatal animal. Moreover, mesenchymal cells appear to be precursors of osteogenic cells.