[The effects of naloxone and electroacupuncture on the release of GnRH from female rat's preoptic area].
By means of push-pull perfusion technique and the special radioimmunoassay we determined the GnRH concentration of the perfusates from preoptic area (POA) in ovariectomized (OVX) and intact (INT) female rats, to observe the influence of naloxone and electroacupuncture (EA) on the release of GnRH and beta-endorphin from POA. The results show that the basic GnRH level of POA perfusate in OVX was 271.8 +/- 77.5pg/ml and that in INT was 52.4 +/- 11.1pg/ml. There was a significant difference between the basic levels of two groups (P < 0.02, n = 12). No difference of beta-endorphin basic level in OVX and INT was found. The GnRH level of POA perfusate in OVX was increased by 146.6 +/- 46.5pg/ml (P < 0.01, n = 12) 30 minutes after intraperitoneal administration of naloxone, but no obvious change was found in INT following naloxone administration. EA treatment had no effect on the release of GnRH and beta-endorphin in both OVX and INT. The results suggest that the negative feedback of estrogen may be a major regulative factor of GnRH under the normal condition and after the abolition of estrogen feedback induced by ovariectomy the central opioid peptide might be the main regulative mechanism for GnRH.
Chen
B
B
Department of Neurobiology, Shanghai Medical University.
Gao
H
H
Ji
S
S
D000818:Animals; D015671:Electroacupuncture; D005260:Female; D007987:Gonadotropin-Releasing Hormone / Q000378:metabolism*; D009270:Naloxone / Q000494:pharmacology*; D010052:Ovariectomy; D011301:Preoptic Area / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar
D007987:Gonadotropin-Releasing Hormone; D009270:Naloxone