Relationship between occupied form of nuclear estrogen receptor and cytosolic progesterone receptor or DNA synthesis in uteri of estradiol implanted rats.
The effect of 17 beta-estradiol (E2) implantation on the cytosolic progesterone receptor (RcP), DNA and occupied form of nuclear estrogen receptor (o- Rn) content in the uterus of ovariectomized adult rats, is described. Animals were implanted with oil or E2-oil solution in Silastic capsules. The latter group animals were divided into two subgroups: in subgroup (a), capsules remained in situ until decapitation time. In subgroup (b) they were removed 48 h after implantation. The E2 implantation caused a significant increase in uterine weight, RcP and o-Rn content 48 h later. However, the DNA content increased significantly only after 72 h, but there was no significant difference in the t-Rn concentration in relation to the non-estrogenized animals. In subgroup (a) animals, these values remained unchanged until 96 h. In subgroup (b), the removal of E2 implants 48 h later caused an almost complete return to the values before the E2 implantation in terms of uterine weight, RcP and o-Rn content. However the DNA concentration remained higher and the t-Rn level was lower than those values that were obtained for the non- estrogenized rats. These results suggest that the RcP and DNA synthesis induced by E2 would be connected to the level of o-Rn, although a closer dependency over time seems to exist between the o-Rn and RcP levels than between the o-Rn and DNA concentrations.
Castellano-Díaz
E
E
Departamentos de Farmacología y Fisiología, Colegio Universitario de Las Palmas, Spain.
González-Quijano
M I
MI
Díaz-Chico
B N
BN
D000818:Animals; D003314:Corn Oil / Q000008:administration & dosage / Q000494:pharmacology*; D004343:Drug Implants; D004958:Estradiol / Q000008:administration & dosage / Q000494:pharmacology*; D005260:Female; D009929:Organ Size / Q000187:drug effects; D010052:Ovariectomy; D010938:Plant Oils / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains; D011980:Receptors, Progesterone / Q000032:analysis* / Q000187:drug effects; D013997:Time Factors; D014599:Uterus / Q000032:analysis / Q000187:drug effects*
D004343:Drug Implants; D010938:Plant Oils; D011980:Receptors, Progesterone; D004958:Estradiol; D003314:Corn Oil