Insulin and insulin-like growth factor-I can trigger the differentiation of catecholaminergic precursors in cultures of dorsal root ganglia

摘要: Avian sensory ganglia contain a population of normally latent autonomic-type precursors with noradrenergic potentialities. Their differentiation in vitro into cells expressing tyrosine hydroxylase immunoreactivity is acutely dependent on the presence one or more substances found chick embryo extract (CEE). We have used cultures dissociated dorsal root from embryonic quail as model system which to assay factors promoting catecholaminergic differentiation, latter being appreciated quantitatively terms number hydroxylase-positive present after 6 days vitro; over large range concentrations, such directly proportional amount CEE medium. In course attempts replace by defined bioactive molecules, we that epidermal growth factor, fibroblast factor nerve possessed negligible, only marginal, differentiation-promoting activity. contrast, insulin, at nanomolar levels, triggered expression phenotype well did CEE. Insulin-like factor-I, similar had an analogous effect. It suggested insulin-like molecule may play role normal sympathoblast vivo.