Growth hormone and the adipose conversion of 3T3 cells.

Cultured preadipose 3T3 cells are induced or enabled to undergo adipose conversion in the presence of an extract of pituitary gland. Adipogenic activity is found in standard growth hormone preparations derived from different species. Further purification of rat growth hormone by several methods does not remove its adipogenic activity. Human growth hormone synthesized in Escherichia coli is also effective. Adipogenic activity is not associated with other pituitary polypeptides. Since growth hormone acts on preadipose cells in the absence of any other cell type, a mechanism exists for the direct participation of the pituitary gland in the regulation of this form of mesenchymal differentiation.