On the evocability of a positive oestrogen feedback action on LH secretion in female and male rats.
Following a single injection of oestradiol benzoate (15 mug/100 g body weight) postpubertally castrated and oestrogen-primed female rats showed a distinct surge of LH secretion, while castrated and androgen-primed  females displayed a diminished and delayed surge of LH secretion. On the other hand, postpubertally castrated and oestrogen-primed male rats exhibited only a slight, but significant surge of LH secretion, whereas castrated and androgen-primed males did not display any surge of LH secretion following oestrogen injection. In view of these findings the evocability of a positive oestrogen feedback action on LH secretion is dependent on the sex hormone level during the critical hypothalamic differentiation phase and the functional (priming) phase as well.
D000367:Age Factors; D000818:Animals; D002369:Castration; D004958:Estradiol / Q000494:pharmacology*; D004967:Estrogens / Q000502:physiology; D005246:Feedback; D005260:Female; D007030:Hypothalamo-Hypophyseal System / Q000502:physiology; D007986:Luteinizing Hormone / Q000378:metabolism*; D008297:Male; D051381:Rats; D012737:Sex Factors; D013739:Testosterone / Q000494:pharmacology; D013997:Time Factors
D004967:Estrogens; D013739:Testosterone; D004958:Estradiol; D007986:Luteinizing Hormone