Dissociation of the stimuli for cell hypertrophy and cell division in the dog thyrocyte: insulin promotes protein accumulation while TSH triggers DNA synthesis.
Thyrotropin through the cyclic AMP cascade, and in the presence of insulin or IGF-1, activates the proliferation of dog thyroid cells. In this work it is shown that insulin, presumably acting through the IGF-1 receptors, stimulates the accumulation of protein and increases cell mass but does not induce DNA synthesis. TSH, on the contrary, induces DNA synthesis, in the presence of insulin, but not protein accumulation. It is proposed that insulin induces the increase of cell mass that is a prerequisite for the mitogenic effect of TSH.
D000818:Animals; D002455:Cell Division / Q000187:drug effects; D048429:Cell Size / Q000187:drug effects; D002478:Cells, Cultured; D004247:DNA / Q000096:biosynthesis*; D004285:Dogs; D007328:Insulin / Q000494:pharmacology*; D014176:Protein Biosynthesis; D013961:Thyroid Gland / Q000166:cytology* / Q000378:metabolism; D013972:Thyrotropin / Q000494:pharmacology*
D007328:Insulin; D013972:Thyrotropin; D004247:DNA