The expression of estrogen receptor genes in diethylstilbestrol-induced pituitary prolactinoma in rats / 中华内分泌代谢杂志

ABSTRACT

Objective　To examine the expressions of estrogen receptor α (ERα), estrogen receptor β (ERβ) and pituitary-specific truncated estrogen receptor product-1 (TERP-1) in diethylstilbestrol (DES) induced prolactinoma of rats. Methods　Ovariectomised Wistar rats were subcutaneously implanted with an implant containing 20 mg DES. Rats were implanted with a blank implant as controls. Eight weeks later, serum prolactin level of rats was measured by RIA. Prolactin immunoreactive cells of anterior pituitary were detected by immunohistochemistry assay. ERα, ERβ and TERP-1 mRNAs in pituitaries were examined by RT-PCR. Results　Serum prolactin levels, pituitary weights and pituitary prolactin immunoreactive cell countings in experimental group rats were all obviously higher than those in control group (P＜0.001 respectively). ERα, ERβ and TERP-1 mRNAs were all transcripted in DES induced rat prolactinomas. ERα and TERP-1 mRNA levels were significantly higher in experimental group than those in control group (P＜0.001 and P＜0.05). Conclusion　Estrogen plays a direct role in regulating pituitary prolactin cells through estrogen receptors. Further functional studies will be required to determine whether coexpression of ER variants along with normal ER confers a pathophysiological role in pituitary hormone regulation and (or) tumor cell proliferation.