Oestrogen positive feedback stimulates the synthesis of LHRH mRNA in neurones of the rostral diencephalon of the rat.
Our aim was to determine whether oestrogen administered to ovariectomized rats in a manner which stimulates the release of LHRH also stimulates the synthesis of LHRH mRNA. Adult female Wistar rats were ovariectomized under halothane anaesthesia between 09.00 and 11.00 h of dioestrus, immediately injected with either oil or 10 micrograms oestradiol benzoate (OB) and then killed by cervical dislocation between 16.00 and 17.00 h of the next day (presumptive pro-oestrus). In-situ hybridization carried out with a 30 mer, 32P-labelled, oligonucleotide probe complementary to LHRH mRNA showed that the concentrations of LHRH mRNA in perikarya in the medial preoptic area, diagonal band and medial septum were significantly greater in OB-compared with oil-treated rats. Plasma LH concentrations were significantly increased in three out of four of the OB-treated rats. These results show for the first time that as well as stimulating LHRH and LH release, oestrogen positive feedback also stimulates the synthesis of LHRH mRNA.
Rosie
R
R
MRC Brain Metabolism Unit, University Department of Pharmacology, Edinburgh.
Thomson
E
E
Fink
G
G
D000818:Animals; D004958:Estradiol / Q000494:pharmacology*; D005246:Feedback; D005260:Female; D007987:Gonadotropin-Releasing Hormone / Q000235:genetics*; D007031:Hypothalamus / Q000166:cytology; D007032:Hypothalamus, Anterior / Q000187:drug effects / Q000378:metabolism*; D007986:Luteinizing Hormone / Q000097:blood; D009474:Neurons / Q000187:drug effects / Q000378:metabolism*; D010052:Ovariectomy; D012333:RNA, Messenger / Q000096:biosynthesis*; D051381:Rats; D011919:Rats, Inbred Strains
D012333:RNA, Messenger; D007987:Gonadotropin-Releasing Hormone; D004958:Estradiol; D007986:Luteinizing Hormone