Progesterone regulation of progesterone receptor in mesometrial and antimesometrial deciduoma in pseudopregnant hamster.
Experiments were performed to examine the trophic effects of progesterone (P) on the progesterone receptor (PR) and the maintenance of the deciduoma. Deciduomal reactions in response to artificial stimuli were induced in hamsters' uteri on the 4th (D4) day of pseudopregnancy (PSP). On and after the 8th day, PSP hamsters received P supplement (2mg; s.c.) daily. Histological observation revealed that the life span of the deciduoma was partially prolonged. The maintenance and regression of the deciduoma was heterogeneous. P was able to maintain the morphology of the cells at the mesometrial site (MS) on D12, whereas cells at the antimesometrial site (AMS) regressed. The cytosol progesterone receptor (cPR) concentration in cells of the MS was higher than that of the AMS on D10. The cPR in MS and AMS decreased drastically on D12. The nuclear PR (nPR) remained at a higher concentration in both tissues on D10 followed by a precipitous decrease. The deciduomal nPR in the AMS decreased at a faster rate. By day 12, the nPR in the MS was much higher than that in the AMS. These data show that P acts as a trophic hormone of the deciduoma. The maintenance of deciduoma is closely related to the presence of PR. Other mechanisms may exist for the heterogeneous responses observed at the MS and AMS.
Jow
G M
GM
Department of Physiology, College of Medicine, National Taiwan University, Taipei, Republic of China.
Chen
T J
TJ
D000818:Animals; D006224:Cricetinae; D003656:Decidua / Q000166:cytology / Q000187:drug effects*; D005260:Female; D008647:Mesocricetus; D011247:Pregnancy; D011374:Progesterone / Q000494:pharmacology*; D011555:Pseudopregnancy; D011863:Radioimmunoassay; D011980:Receptors, Progesterone / Q000378:metabolism*
D011980:Receptors, Progesterone; D011374:Progesterone