[Effect of Chinese herbal medicine for nourishing yin and removing fire on biosynthesis, secretion and regulative mechanism of gonadotropin-releasing hormone in hypothalamus].
OBJECTIVE
To elucidate the effect of Chinese herbal medicine (CHM) for nourishing Yin and removing fire on the biosynthesis, secretion and regulative mechanism of gonadotropin-releasing hormone (GnRH) in hypothalamus.


METHODS
The brain slices of medial basal hypothalamus of adolescent rats, which had been fed with CHM, were incubated. The content of GnRH in incubative liquid was determined during the slices were stimulating with high KC1 to observe the change of GnRH biosynthesis from tonic secretory center of GnRH (arcuate nucleus and ventromedial nucleus) in hypothalamus. The integrated optic density of GnRH positive immunoreactive substance in preoptic area of hypothalamus was determined by immunohistochemistry and image processing to observe the change of GnRH content in pulsative secretory center of GnRH (medial preoptic nucleus) in hypothalamus. The push-pull perfusion of medial preoptic area in hypothalamus was performed. The content of GnRH in serial perfusates was determined by radioimmunoassay (RIA) to observe the change of frequency and amplitude of GnRH pulse releasing from medial preoptic area in hypothalamus. The content of aspartic acid, glutamic acid and gamma-amino butyric acid in the perfusate was determined by high performance liquid chromatography-fluorometry, and the content of beta-endorphic in the perfusate was determined by RIA to observe the change of releasing amount of exciting aminoacid neurotransmitter and beta-endorphin from pulsative secretory center of GnRH (medial preoptic area) in hypothalamus.


RESULTS
CHM could markedly reduce the content of GnRH in medial basal hypothalamus (arcuate nucleus and veatromeolial nucleus) and preoptic area (meolical preoptic nucleus) of hypothalamus, and could obviously lower the frequency and amplitude of GnRH pulse releasing from medial preoptic nucleus, It also could markedly decrease the releasing amount of aspartic acid and glutamic acid, while obviously increase the releasing amount of gamma-amino butyric acid and beta-endorphin from medial preoptic area of hypothalamus.


CONCLUSIONS
CHM could markedly reduce the activity of GnRH neurons in hypothalamus through inhibiting the releasing of central exciting aminoacid neurotransmitter and promoting the releasing of central inhibiting aminoacid neurotransmitter and beta-endorphin, thereby, obviously decrease the biosynthesis and secretion of GnRH from tonic and pulsative secretory center of GnRH in hypothalamus. It could be one of chief effective mechanism of CHM in efficiently treating the idiopathic precocious puberty.
Cai
D P
DP
Pediatric Hospital, Medical School, Fudan University, Shanghai 200032.
Chen
B Y
BY
Zhuang
Z J
ZJ
D000818:Animals; D001111:Arcuate Nucleus of Hypothalamus / Q000378:metabolism; D004365:Drugs, Chinese Herbal / Q000494:pharmacology*; D005260:Female; D007987:Gonadotropin-Releasing Hormone / Q000096:biosynthesis* / Q000378:metabolism; D007031:Hypothalamus / Q000378:metabolism*; D008297:Male; D011301:Preoptic Area / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D001615:beta-Endorphin / Q000096:biosynthesis; D005680:gamma-Aminobutyric Acid / Q000096:biosynthesis
D004365:Drugs, Chinese Herbal; D007987:Gonadotropin-Releasing Hormone; D005680:gamma-Aminobutyric Acid; D001615:beta-Endorphin