97 HUMAN FETAL AND ADULT CHONDROCYTES: CLONAL GROWTH PROMOTION BY INSULIN LIKE GROWTH FACTORS I AND II, INSULIN AND GROWTH HORMONE

Abstract

A direct assay for cellular growth was used. It measures the capacity of isolated chondrocytes to proliferate in a clonal manner starting from a single cell suspension in a semisolid system (0.8% methylcellulose, BM Whissler Medium, 5% heat inactivated serum, 1000 inserted chondrocytes/ml). This assay was used to measure the clonal proliferation of human fetal (20th week of pregnancy, n=10) and adult articular chondrocytes 20yrs, n= 10) in response to insulin like growth factors I and II (IGF I/II), biosynthetic human insulin (BHI) and human growth hormone (hGh). Both BHI (100 ng/ml) and hGh (100 ng/ml) did not stimulate fetal and adult chondrocytes to proliferate in a clonal manner. IGF I (25 ng/ml) stimulated clonal growth of fetal chordrocytes (60 ± 12 colonies/1000 inserted cells; m ± 1 SD), however IGF II (25 ng/ml) was significantly more effective (116 ± 12 colonies/1000 inserted cells; p < 0.05). In contrast IGF I was more effective in adult chondrocytes (40 ± 5 colonies/1000 inserted cells) than IGF II (24 ± 2 colonies/1000 inserted cells; p < 0.05).