IDENTIFICATION AND CHARACTERIZATION OF VARIOUS DIFFERENTIATIVE GROWTH-PLATE CHONDROCYTES FROM PORCINE BY COUNTERCURRENT CENTRIFUGAL ELUTRIATION

Countercurrent centrifugal elutriation was used to separate growth pla te chondrocytes from porcine basing on their differences in sizes and densities. Eighteen fractions of cells with different sizes and densit ies were obtained. The mean cellular volumes increased progressively i n each of successive fractions, and that increase was associated with specific phenotypic changes, such as biochemical differences in DNA sy nthesis, proteoglycan synthesis, and activities of alkaline phosphatas e. Three distinct chondrocyte subpopulations with their unique charact eristics were identified among the elutriated fractions. The resting c hondrocytes were found to be small in size and quiescent. The hypertro phic chondrocytes were found to be large in size and metabolically act ive both in alkaline phosphatase and in proteoglycan productions. The proliferative chondrocytes exhibited a high DNA synthesis rate, and th eir sizes were found to be between those of the resting and hypertroph ic chondrocytes. (C) 1996 Wiley-Liss, Inc.