Postnatal ovary is necessary for the maturation of estradiol-induced luteinizing hormone and prolactin surges in female rats.
The role of postnatal ovary in the maturation of estradiol (E2)-induced luteinizing hormone (LH) and prolactin (PRL) surges was examined in female rats of Wistar-Imamichi strain. Animals were bilaterally ovariectomized at 24 h after birth, 1 week (w), 2 w, 3 w, 4 w or 6 w of age. At about 10 w of age, every group was primed with estradiol benzoate (E2B) for two days, and on the third day was decapitated at either 0900 h or 1900 h. Anterior pituitary (AP) LH and PRL content was determined in every group of no E2B treatment. Surge-like secretions of LH and PRL were observed at 1900 h, only in rats ovariectomized on or after 4 w of age. AP LH and PRL content was the higher, as ovariectomy was delayed. These results indicate that postnatal ovary is necessary for the maturation of E2-induced LH and PRL surges. Such an effect of ovary is mediated at least by its stimulation of AP LH and PRL content.
D000818:Animals; D000831:Animals, Newborn / Q000502:physiology*; D004958:Estradiol / Q000494:pharmacology*; D005260:Female; D007986:Luteinizing Hormone / Q000378:metabolism*; D010052:Ovariectomy; D010053:Ovary / Q000502:physiology*; D010507:Periodicity; D010903:Pituitary Gland, Anterior / Q000187:drug effects / Q000378:metabolism; D011388:Prolactin / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains
D004958:Estradiol; D011388:Prolactin; D007986:Luteinizing Hormone