[Studies on the interaction of prolactin and estrogen in rabbit ovary and uterus (author's transl)].
The biological effects of prolactin (PRL) on the uterus and ovary, and the cooperative action of PRL and estrogen to these tissues were investigated in the female white rabbit. 1) Estrogen receptor (ER), progesterone receptor (PR, not in ovary) and PRL receptor were demonstrated in the rabbit uterus and ovary. The dissociation constant determined by Scatchard analysis was approximately at the level from 10(-10)M to 10(-9)M in each ligand binding to receptor. 2) In the pseudopregnant rabbit, b-PRL (30 iu/kg) increased the uterine and ovarian weight (p less than 0.001, p less than 0.01 respectively) but neither altered the steroid levels, nor the uterine and ovarian cytoplasmic ER levels. In the uterus, b-PRL increased the PRL receptor levels and tended to increase the nuclear ER levels. 3) In the ovariectomized immature rabbit, b-PRL (30 iu/kg) increased in uterine weight (p less than 0.05), decreased the uterine cytoplasmic ER levels (p less than 0.05), but increased the nuclear ER levels (p less than 0.05). With estrogen, b-PRL increased the uterine weight (p less than 0.05); tended to increase the cytoplasmic and nuclear ER levels, and increased the cytoplasmic PR levels (p less than 0.05). 4) In the ovariectomized immature rabbit, b-PRL did not change the histological finding of the uterus, whether estrogen was primed or not. In the pseudopregnant rabbit, b-PRL accelerated the progestational proliferation of the uterus. These results indicated that PRL demonstrated the biological effect on the rabbit uterus and ovary directly via PRL receptor, and that PRL enhances the estrogenic action, giving the effect on the mechanisms related with ER in the rabbit uterus.
D000818:Animals; D002369:Castration; D004958:Estradiol / Q000097:blood; D005260:Female; D009929:Organ Size / Q000187:drug effects; D010053:Ovary / Q000032:analysis / Q000187:drug effects*; D011374:Progesterone / Q000097:blood; D011388:Prolactin / Q000494:pharmacology*; D011817:Rabbits; D011956:Receptors, Cell Surface / Q000032:analysis; D011960:Receptors, Estrogen / Q000032:analysis*; D011980:Receptors, Progesterone / Q000032:analysis; D011981:Receptors, Prolactin; D014599:Uterus / Q000032:analysis / Q000187:drug effects*
D011956:Receptors, Cell Surface; D011960:Receptors, Estrogen; D011980:Receptors, Progesterone; D011981:Receptors, Prolactin; D011374:Progesterone; D004958:Estradiol; D011388:Prolactin