Endocrine Abstracts

Circulating levels of prolactin are subject to acute and long-term regulation by many factors including oestrogen and dopamine. We have studied the regulation of prolactin promoter activity in living pituitary cells using transgenic Fischer rats in which reporter gene expression is regulated by the human prolactin gene locus (hPRL-d2EGFP). We have previously identified pulsatile prolactin transcription patterns in living lactotroph cells in fetal tissue, that became stabilised...

Prolactinomas are the commonest type of functioning pituitary adenoma in man. High circulating oestrogen levels are associated with lactotroph proliferation and increased PRL secretion essential for lactation. In vitro, oestradiol induces proliferation of the rat pituitary somatolactotroph GH3 cell line, and chronic oestrogen treatment of Fischer-344 rats in vivo results in lactotroph hyperplasia and adenoma formation, though the mechanisms responsible remain elu...