EFFECT OF GROWTH-FACTORS ON THE PROLIFERATION OF LIGAMENT FIBROBLASTSFROM SKELETALLY MATURE RABBITS

Growth factors have been shown to stimulate fibroblast proliferation d uring wound and ligament healing, In this study, we analyzed individua l effects of eight growth factors in vitro on the proliferation of fib roblasts from the medial collateral (MCL) and anterior cruciate (ACL) ligaments of skeletally mature rabbits, We compared the proliferative response of growth factor-treated and nontreated fibroblasts of both l igaments, The growth-factor treated fibroblasts of the MCL and ACL wer e also compared. We found that the fibroblasts exposed to epidermal gr owth factor, basic fibroblast growth factor and platelet-derived growt h factor-BE proliferated significantly more than untreated fibroblasts , Acidic fibroblast growth factor at a dose of 1.0 ng/ml caused signif icant increases in fibroblast proliferation only in the MCL, Transform ing growth factor-beta 1, insulin-like growth factor-1, platelet-deriv ed growth factor-AA, and interleukin-1 alpha did not significantly sti mulate fibroblast proliferation, MCL fibroblasts generally did not pro liferate significantly more than ACL fibroblasts with the exception of MCL fibroblasts exposed to the highest doses of basic fibroblast grow th factor, acidic fibroblast growth factor and platelet-derived growth factor-BE, The data were also compared with those obtained earlier us ing fibroblasts from skeletally immature rabbits (Schmidt et al., JOR 1995), The proliferative response of both the MCL and the ACL fibrobla sts was found to decrease with skeletal maturation, Thus, our findings suggest that animal age and fibroblast origin are important factors i n determining the proliferative response to growth factors.