Alterations in electrophysiology of cultured BALB/cfC3H mouse mammary epithelium associated with neoplastic...

Mammary tumor virus and neoplastic transformation affect prolactin-modulated electrophysiology of mouse mammary epithelium in vitro. Transepithelial resistances of both prelactating and neoplastic BALB/cfC3H mouse mammary epithelial cell cultures are lower than those seen in BALB/c prelactating cell cultures. Unlike the response to prolactin in BALB/c cultures, there are no effects of this hormone on transepithelial potential difference or resistance of BALB/cfC3H prelactating or neoplastic cultures. However, prolactin significantly increases short-circuit current in both BALB/c and BALB/cfC3H prelactating cell cultures and in BALB/cfC3H neoplastic cell cultures. The response of tumor cell cultures suggests that pregnancy-independent mouse mammary epithelium may not be entirely refractory to prolactin.