The influence of purified somatomedins and insulin on foetal rat brain DNA synthesis in vitro.

The two main forms of somatomedins, termed insulin-like growth factor I and II (IGF-I and IGF-II), have been isolated from human plasma. Pure IGF-I or IGF-II was incubated with foetal rat brain cells and found to be equipotent in stimulating the [3H]thymidine incorporation into DNA, despite the fact that IGF-I not is present during foetal life.