Hormonal effects on rat mammary gland in vitro.

The mammogenic and lactogenic effect of various hormones on rat mammary gland has been studied in vitro using an organ culture technique. The effects have been assessed mainly by light microscopy. The study has been confined mainly to the effects and interactions of the lactogenic protein hormones, corticosteroids and progesterone. It establishes the importance of the presence of insulin and serum and of the type of serum for the hormonal effects in vitro. These effects have been studied mainly on the explants obtained from 13 days pregnant rats. In addition explants from non-pregnant rats and at various stages of pregnancy and lactation were studied.