H. Syvala et al., HORMONE-DEPENDENT CHANGES IN A-FORM AND B-FORM OF PROGESTERONE-RECEPTOR, Journal of steroid biochemistry and molecular biology, 58(5-6), 1996, pp. 517-524
The influence of different estrogen and/or progesterone treatments on
concentrations of A and B forms of progesterone receptor (PR-A and PR-
B) in the different cell types of chick oviduct was studied. A semiqua
ntitative immunohistochemical assay for cellular PR concentrations was
developed using a computer-assisted image analysis system. The staini
ng intensity of nuclear PR in the basal layer of epithelial cells, gla
ndular, smooth muscle and mesothelial cells was analysed separately us
ing two monoclonal antibodies, PR6 and PR22. The measured concentratio
ns of PR varied between different cell types and from cell to cell. A
significant decrease in PR concentration, as noted by a decrease in st
aining intensity, was observed in all cell types studied 2 or 6 h afte
r a single injection of progesterone with or without simultaneous estr
ogen administration. The decrease was also verified with immunoblottin
g and an immunoenzymometric assay (IEMA) for chicken PR. After down-re
gulation the concentration of PR recovered to the control level within
48 h after progesterone or estrogen administration. Estrogen administ
ration alone was observed to cause changes in the concentration of PR-
A only, having little or no effect on PR-B concentration depending on
the cell type studied. These findings indicate that estrogen and proge
sterone cause cell-specific changes not only to the total concentratio
n of PR but also to the cellular ratio of PR-A and PR-B. Copyright (C)
1996 Elsevier Science Ltd