[Effects of kidney-tonifying Chinese herbal medicine on hypothalamic-pituitary gonadotrophic function].
OBJECTIVE
To observe the effects of kidney-tonifying Chinese herbal medicine on the synthesis and secretion of gonadotropin releasing hormone (GnRH) and the related neurotransmitters and neuropeptides, and to explore the mechanism of the regulative effect of Chinese herbal medicine on the hypothalamic-pituitary gonadotrophic function.


METHODS
Female Sprague-Dawley rats during the period of normal adolescent initiation (160-180 g, 1.5 months) were randomly divided into three groups. The control group was fed with normal saline and the two experimental groups were fed with Chinese herbal medicine for nourishing yin to reduce fire (Zi Yin Xie Huo, ZYXH) or nourishing kidney to replenish essence (Yi Shen Tian Jing, YSTJ) respectively. The dosage was 5 ml/d for 30 days by gastric gavage. Integrated optic densities of the GnRH and neuropeptide Y (NPY) in medial preoptic area (MPOA), arcuate nucleus (ARC) and median eminence (ME) of hypothalamus were determined by immunohistochemistry method and image processing. The content of GnRH in homogenate of hypothalamus preoptic area was determined by radioimmunoassay (RIA). The releasing amount of monoamine neurotransmitters from medial basal hypothalamus (MBH) was determined by brain slices incubation and high pressure liquid chromatography (HPLC). The releasing amount of GnRH and NPY from POA was determined by push-pull perfusion and RIA, and the releasing amount of monoamine neurotransmitters from this site was determined by HPLC.


RESULTS
ZYXH could inhibit the synthesis and secretion of GnRH from periodic and tonic secretory centers of GnRH, while YSTJ could stimulate the synthesis and secretion of GnRH from the both secretory centers of GnRH. ZYXH could inhibit the activity of GnRH neurons via diminishing the releasing of norepinephrine (NE) from tonic secretory center of GnRH, increasing the releasing of dopamine (DA) in periodic secretory center of GnRH and increasing the synthesis and releasing of NPY from the both secretory centers of GnRH, it hence inhibited the hypothalamic-pituitary gonadotrophic function. YSTJ could stimulate the activity of GnRH neurons via diminishing the synthesis and releasing of NPY from tonic secretory center of GnRH, it hence promoted the hypothalamic-pituitary gonadotrophic function.


CONCLUSIONS
Chinese herbal medicine for tonifying the kidney could modulate hypothalamic-pituitary gonadotrophic function via regulating the synthesis and secretion of GnRH and the related neurotransmitters (NE, DA) and neuropeptides (NPY).
Shen
Hao
H
Department of Integrated Traditional Chinese and Western Medicine, Pediatric Hospital, Fudan University, Shanghai 200032, China. haoshen518@163.com
Cai
De-Pei
DP
Chen
Bo-Ying
BY
D000818:Animals; D004298:Dopamine / Q000378:metabolism; D004365:Drugs, Chinese Herbal / Q000494:pharmacology*; D005260:Female; D007987:Gonadotropin-Releasing Hormone / Q000096:biosynthesis*; D007030:Hypothalamo-Hypophyseal System / Q000187:drug effects*; D007668:Kidney / Q000187:drug effects*; D009478:Neuropeptide Y / Q000096:biosynthesis; D009638:Norepinephrine / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley
D004365:Drugs, Chinese Herbal; D009478:Neuropeptide Y; D007987:Gonadotropin-Releasing Hormone; D004298:Dopamine; D009638:Norepinephrine