Effects and differentiation activity of IGF-I, IGF-II, insulin and preptin on human primary bone cells.

The importance of the complex interrelated regulatory pathways involving IGF factors and pancreatic hormones can be observed in several metabolic diseases, where the deregulation of these factors has a wide impact on bone health. These findings have stimulated us to compare the effect of IGF-I, IGF-II, insulin and preptin on human bone cells. The effect on cell differentiation and cell activity of osteoblasts and osteoclasts has been analysed. We have observed a significant effect by IGF-I, a modest effect by IGF-II and preptin and no effect after insulin administration on human primary osteoblast-like cells. All studied factors have shown an induction on human primary osteoclast differentiation and bone resorption activity, with IGF-I being the most potent factor. We hypothesize that these findings may be on the basis of decreased bone mass density observed in several diseases.