Estrogen modulation of osteoblastic cell-to-cell communication.
Two osteoblastic cell populations, calvarial and marrow stromal cells, were exposed to estrogen derivatives in vitro. The hormonal effect was monitored by following intracellular Ca+2 levels [Ca+2]i and gap-junction communication. We measured fast changes in intracellular Ca+2 levels in response, of these cells, to the steroid hormones. The changes were dose dependent revealing maximal activity at 100 pM by 17-beta-Estradiol and 1 nM by estradiol-CMO. Additionally, the effect of estrogen, on functional coupling of the cells, was measured using fluorescence dye migration and counting the number of neighboring cells coupled by gap junctions. An uncoupling effect was demonstrated in response of these cells to estrogen treatment. The quick stereospecific effect was achieved in the presence of 17-beta-estradiol but not in the presence of 17-alpha-estradiol. These results suggest the involvement of plasma membrane receptors in addition to the already known nuclear receptors in transducing the hormone effects in the osteoblastic cells.
Massas
R
R
Department of Physiology and Pharmacology, Sackler Faculty of Medicine, Tel Aviv University, Israel.
Korenstein
R
R
Benayahu
D
D
D000818:Animals; D000831:Animals, Newborn; D002118:Calcium / Q000378:metabolism; D002450:Cell Communication / Q000187:drug effects*; D002478:Cells, Cultured; D004965:Estrogen Antagonists / Q000494:pharmacology; D004967:Estrogens / Q000494:pharmacology*; D010006:Osteoblasts / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D051381:Rats; D013629:Tamoxifen / Q000494:pharmacology
D004965:Estrogen Antagonists; D004967:Estrogens; D013629:Tamoxifen; D002118:Calcium