A recombinant IGF-1 analogue stimulates [3H]thymidine incorporation in human epiphyseal growth cartilage in vitro.

The effect of a recombinant analogue of IGF-1 on human cartilage of different ages has been investigated in vitro. Addition of 100 ng/ml IGF-1 to articular and epiphyseal growth plate cartilage (9 months to 16 years) resulted in an increase in [3H]thymidine incorporation to a mean of 130 +/- 4% (SE) and 378 +/- 53% of controls, respectively. In costal and growth cartilage from normal fetuses of 15-18 weeks gestation, [3H]thymidine incorporation was increased to 119 +/- 3 and 133 +/- 11% of controls, respectively, when 100 ng/ml IGF-1 was added. The mitogenic effect of recombinant IGF-1 in vitro extends to human cartilage and is most notable in postnatal epiphyseal growth plate.