RESUMO
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.
RESUMO
Radioimmunoassay of human plasma ACTH was developed. Rabbit was immunized by a1-28 ACTH conjugated to BSA. A specific antiserum with an optimal dilution of 1:32,000-60,000 was obtained. The radioiodination of a1-28 ACTH was processed by chloramine-T oxidation-sodium metabisulfite method, and the radiochemical purity of 125I-a1-28 ACTH was about 90-95.5% . The sensitivity of the present assay was 4 pg/ml, with a range of 10-640 pg/ml. The intraassay coefficient of variation was 2.3-7.0% while the interassay coefficient of variation 8.5-8.8%.The concentration of human plasma ACTH was determined by this assay in 20 healthy adults, and the results ranged from 10-90 pg/ml at SAM. The levels of plasma ACTH showed apparent circadian periodicity. In five patients the results of plasma ACTH were consistent with their clinical diagnoses.