- Regulation of Estrogen Receptor mRNA in Rat Anterior Pituitary Gland.
-
Min Seok Chun, Duck Bae Park, Yong Bin Park, Kyung Yoon Kam, Chang Mi Kim, Kyung Ja Yoo
-
J Korean Endocr Soc. 1997;12(4):518-527. Published online January 1, 2001
-
-
-
Abstract
PDF
- The estrogen receptor (ER) is present in a wide variety of mammalian tissues and is required for the physiological responses of estrogen, including estrogen-induced tissue-specific changes in gene expression. But most of our knowledge on the regulation of ER mRNA levels comes from in vivo steroid replacement experiments or cancer cell lines that express the ER. Thus the present study was attempted to determine 1) the anterior pituitary ER mRNA levels during rat estrous cycle 2) if estradiol itself directly modulates the ER mRNA levels in cultured rat anterior pituitary using RT-PCR method. In rats with 4 day estrous cycle, the ER mRNA levels in anterior pituitary gland reached to maximum at proestrus 11:00h just before serum estradiol concentration showed the highest. From then, the ER mRNA levels gradually declined during the rest of the proestrus. On the other hands, in cultured rat anterior pituitary cells, the ER mRNA levels were significantly decreased by the treatment of estradiol. These results indicate that the surge of estradiol was proceeded by the increase in pituitary ER mRNA levels during the proestrus and in cultured anterior pituitary cells, estrogen might be involved in the down-regulation of the ER mRNA levels.
|