Elevated glandular kallikrein in estrogen-induced pituitary tumors.

Anterior pituitary tumors were induced in F344 rats by implants of diethylstilbesterol (DES) for 8 weeks. DES-induced tumors contained 250 times more glandular kallikrein than anterior pituitaries from rats not exposed to estrogen, and 6.6 times more glandular kallikrein than anterior pituitaries from rats exposed to large doses of estrogen for 10 days. DES-induced anterior pituitary tumors in F344 rats arise from lactotroph proliferation. Thus, the results suggest that anterior pituitary glandular kallikrein is associated with lactotrophs.