[Effect of Chinese herbal medicine for nourishing yin and purging fire on mRNA expressions of gonadotropin-releasing hormone and its receptor in precocious puberty model rats].
OBJECTIVE
To probe the mechanism of Chinese herbal medicine (CHM) for nourishing Yin and purging Fire on the expressions of gonadotropin-release hormone (GnRH) and its mRNA expression in hypothalamus and GnRH receptor mRNA in pituitary in danazol induced precocious puberty model rats.


METHODS
Rats were divided into the normal group, the model group, the blank control group and the CHM group. Rats, except that in the normal group, were subcutaneously administered danazol 300 micrograms at 5 days of age individually and CHM was fed to rats in the CHM group from 15 days of age, in the meantime, normal saline was fed to rats in the blank control group. Expression of GnRH in hypothalamus was observed by immunohistochemical method and expressions of GnRH mRNA in hypothalamus and GnRH receptor mRNA in pituitary were determined by RT-PCR.


RESULTS
Compared with rats in the normal groups, the vaginal opening and the onset of first estrus were ahead of time, the number of GnRH immunoreactive positive cells decreased and the expressions of GnRH mRNA in hypothalamus and GnRH receptor mRNA in pituitary up-regulated in the model rats and blank control rats. Compared with the model and the blank control groups, in CHM group, all the above-mentioned abnormally changed parameters improved significantly after treatment.


CONCLUSIONS
CHM for nourishing Yin and purging Fire may inhibit the abnormal hyperfunction of hypothalamus-pituitary-ovary axis in precocious puberty rat induced by danazol via reducing the synthesis and release of GnRH, and lowering the responsibility of pituitary cells to GnRH. This may be the primary mechanism of CHM in effectively treating the true precocious puberty.
Department of Integrated Traditional Chinese and Western Medicine, Shanghai Medical Center, Fudan University, Shanghai 200032.
Zhan-zhuang
ZZ
Tian
Hong
H
Zhao
Bo-ying
BY
Chen
D000818:Animals; D004365:Drugs, Chinese Herbal / Q000494:pharmacology*; D005260:Female; D007987:Gonadotropin-Releasing Hormone / Q000096:biosynthesis* / Q000235:genetics; D007030:Hypothalamo-Hypophyseal System / Q000378:metabolism; D011629:Puberty, Precocious / Q000378:metabolism*; D012333:RNA, Messenger / Q000096:biosynthesis; D011897:Random Allocation; D051381:Rats; D017207:Rats, Sprague-Dawley; D011966:Receptors, LHRH / Q000096:biosynthesis* / Q000235:genetics; D016710:Yin Deficiency / Q000378:metabolism
D004365:Drugs, Chinese Herbal; D012333:RNA, Messenger; D011966:Receptors, LHRH; D007987:Gonadotropin-Releasing Hormone