Insulin and insulin-like growth factor-I can trigger the differentiation of catecholaminergic precursors in cultures of dorsal root ganglia.
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 of one or more substances found in chick embryo extract (CEE). We have used cultures of dissociated dorsal root ganglia from embryonic quail as a model system in which to assay factors promoting catecholaminergic differentiation, the latter being appreciated quantitatively in terms of the number of tyrosine hydroxylase-positive cells present after 6 days in vitro; over a large range of concentrations, the number of such cells is directly proportional to the amount of CEE in the medium. In the course of attempts to replace CEE by defined bioactive molecules, we found that epidermal growth factor, fibroblast growth factor or nerve growth factor possessed negligible, or only marginal, noradrenergic differentiation-promoting activity. In contrast, insulin, at nanomolar levels, triggered expression of the catecholaminergic phenotype as well as did CEE. Insulin-like growth factor-I, at similar concentrations, had an analogous effect. It is suggested that an insulin-like molecule may play a role in the normal differentiation of sympathoblast precursors in vivo.
Xue
Z G
ZG
Institut d'Embryologie Cellulaire et Moléculaire du CNRS, Nogent-sur-Marne, France.
Le Douarin
N M
NM
Smith
J
J
D000818:Animals; D002395:Catecholamines / Q000378:metabolism*; D002454:Cell Differentiation / Q000187:drug effects; D002478:Cells, Cultured; D005727:Ganglia, Spinal / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism; D007328:Insulin / Q000494:pharmacology*; D007334:Insulin-Like Growth Factor I / Q000494:pharmacology*; D011784:Quail; D013002:Somatomedins / Q000494:pharmacology*
D002395:Catecholamines; D007328:Insulin; D013002:Somatomedins; D007334:Insulin-Like Growth Factor I