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The Ovarian Dysgenesis Normally Induced by Neonatal Thymectomy is Prevented by the Prior Administration of Estrogen
Author(s) -
CHAPMAN JOHN C.,
GRIFFIN WILLIAM J.,
VASSALO MILO F.,
MICHAEL SANDRA D.
Publication year - 1995
Publication title -
american journal of reproductive immunology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.071
H-Index - 97
eISSN - 1600-0897
pISSN - 1046-7408
DOI - 10.1111/j.1600-0897.1995.tb00938.x
Subject(s) - dysgenesis , gonadal dysgenesis , thymectomy , endocrinology , medicine , follicular phase , estrogen , ovariectomized rat , ovary , biology , anatomy , myasthenia gravis
PROBLEM : Neonatal thymectomy (Tx) and estrogen (E 2 ) administration disrupt the reproductive and immune systems of female mice. The current experiment examined the combined effects of the two procedures on ovarian function, performed in sequence, and in reverse sequence. METHOD : Groups of (C57BL/6J × A/J)F, (B6A) female mice were given four daily injections of 20 μg estradiol‐17β, either from 0 days to 3 days, or from 3 days to 6 days postpartum. In some groups this regimen was combined with thymectomy performed either prior to steroid injection (TX‐3), or after steroid treatment (TX‐4). Animals were sacrificed between 100 and 110 days of age then ovaries evaluated via light microscopy for dysgenesis and follicular cysts. RESULTS : When E 2 treatment followed Tx, the incidence of ovarian dysgenesis was unchanged (study 1, Tx + E 2 = 60% ovarian dysgenesis; Tx = 63% ovarian dysgenesis) (study 2, Tx + E 2 = 46% ovarian dysgenesis; Tx = 45% ovarian dysgenesis). In contrast, when E 2 was given before Tx, ovarian dysgenesis did not occur (study 2, E 2 + Tx = 0% ovarian dysgenesis; Tx = 46% ovarian dysgenesis). Ovaries from E 2 + Tx animals were characteristic of ovaries from E 2 ‐injected animals without Tx. CONCLUSION : The results indicate that E 2 injection prevents Tx‐induced ovarian dysgenesis, suggesting E 2 ‐activation of an extrathymic pathway for thymus function.