Effect of estradiol on the progesterone receptor and on morphological ultrastructures in the fetal and newborn uterus and ovary of the rat.
The effect provoked by estradiol after administration to pregnant rats (1 mg per day) was studied in fetal and newborn uteri and ovary. Estrogen receptors are found in the fetuses of non-treated animals. Their number (in fmol/mg DNA, +/- SD) in the fetal uterus (total sites, cytosol + nuclei) was at the age of 18 days: 63 +/- 15; at 20 days 101 +/- 13; and in the 24-h-old newborn; 415 +/- 120. The respective values in the ovary were: 105 +/- 25; 520 +/- 60 and 410 +/- 190. Estradiol stimulated significantly the progesterone receptor in the fetal uterus at 20 days old. The progesterone receptor (in fmol/mg DNA, +/- SD) which was 97 +/- 17 in the non-treated animals, increased to 790 +/- 90 in the E2-primed animals. Newborns, 24-h-old, had no detectable progesterone receptor, but in the E2-treated animals the value increased to 1210 +/- 120. In the fetal ovary of non-treated animals, progesterone receptor at the age of 18 days is: 90 +/- 19; at 20 days 132 +/- 47, and in the newborns 260 +/- 67; in the E2-treated animals, the values are respectively 330 +/- 49; 865 +/- 78 and 1280 +/- 307. In the fetal uteri of E2-treated animals, histological and ultrastructural studies showed an increase in the size of the uterine horn, the height of the epithelial cells, and stromal cell differentiation. It is suggested that, as was extensively demonstrated in the fetal compartment of the guinea-pig, the machinery for estrogen responses operates also during fetal development of the rat.
Nguyen
B L
BL
C.N.R.S. Steroid Hormone Research Unit, Foundation for Hormone Research, Paris, France.
Hatier
R
R
Jeanvoine
G
G
Roux
M
M
Grignon
G
G
Pasqualini
J R
JR
D000818:Animals; D001667:Binding, Competitive / Q000187:drug effects; D002467:Cell Nucleus / Q000648:ultrastructure; D003593:Cytoplasm / Q000648:ultrastructure; D003600:Cytosol / Q000648:ultrastructure; D004958:Estradiol / Q000494:pharmacology*; D005260:Female; D008431:Maternal-Fetal Exchange / Q000187:drug effects; D010053:Ovary / Q000187:drug effects* / Q000378:metabolism / Q000648:ultrastructure; D011247:Pregnancy; D051381:Rats; D011919:Rats, Inbred Strains; D011960:Receptors, Estrogen / Q000187:drug effects; D011980:Receptors, Progesterone / Q000187:drug effects*; D014599:Uterus / Q000187:drug effects* / Q000378:metabolism / Q000648:ultrastructure
D011960:Receptors, Estrogen; D011980:Receptors, Progesterone; D004958:Estradiol