Thymosin fraction 5 stimulates the release of prolactin from cultured GH3 cells

Thymosin fraction 5, a bovine thymus preparation, has recently been implicated in the regulation of neuroendocrine function. The purpose of the present study was to investigate the effects of thymosin fraction 5 treatment upon the GH3 rat pituitary cell line. Thymosin fraction 5 stimulated prolactin (PRL) release from these cells in a dose and time dependent manner. These results suggest that a product of the endocrine thymus may regulate the release of PRL.