Subclones of normal clonal prolactin cells of the rat.

We recently established a clone (2B8) of normal rat prolactin cells that secretes only prolactin into the medium. When grown in the presence of thyrotrophin-releasing hormone (TRH), estradiol (E2) or arginine vasotocin (AVT), the cells show increased production of prolactin. Subclones of single cell origin were developed from 2B8 cells exposed for 1 week to TRH, E2 or TRH plus E2. These subclones differ in their response to TRH, E2 or AVT and therefore may possess different receptors for these hormones.