Receptor-mediated glucocorticoid inhibition of cell proliferation in mouse growth cartilage in vitro.
The growth hormone of neonatal facial cartilage from ICR mice is inhibited by glucocorticoid treatment in vitro. A reduction of the overall tissue weight is accompanied by a substantial decrease in the protein content of the tissue. For the first 48 h in culture, hormone-treated cartilage undergoes a complete standstill in protein gain, and only thereafter the protein content increases, yet is markedly smaller than that of control specimens. Further, a significant reduction in the DNA content is seen already by 24 h, a feature that intensifies by 48 h. A slight recovery takes place thereafter. The reduction in DNA concentration is accompanied by a significant decrease in [3H]thymidine incorporation in acid-insoluble material. The inhibition of DNA synthesis by triamcinolone acetonide is protein- and RNA-synthesis-dependent. Autoradiographic examinations reveal that young cartilage cells are heavily labelled with [3H]dexamethasone and that this labelling is specific. To further substantiate the involvement of glucocorticoid-specific receptors in the latter's inhibitory effects, tissues were treated with cortexolone, this apparently 'masking' the cytosolic receptors for glucocorticoids, and thereby succeeded to eliminate the growth-inhibitory effect of triamcinolone. These results provide evidence for a receptor-mediated set of responses to glucocorticoids in these cartilage cells.
D015065:17-Hydroxycorticosteroids / Q000494:pharmacology*; D000818:Animals; D001345:Autoradiography; D002356:Cartilage / Q000166:cytology* / Q000187:drug effects; D002455:Cell Division / Q000187:drug effects*; D002478:Cells, Cultured; D003350:Cortodoxone / Q000494:pharmacology*; D003513:Cycloheximide / Q000494:pharmacology; D004247:DNA / Q000096:biosynthesis; D003609:Dactinomycin / Q000494:pharmacology; D051379:Mice; D008813:Mice, Inbred ICR; D011506:Proteins / Q000378:metabolism; D011691:Puromycin / Q000494:pharmacology; D011965:Receptors, Glucocorticoid / Q000187:drug effects*; D011987:Receptors, Steroid / Q000187:drug effects*; D014222:Triamcinolone Acetonide / Q000494:pharmacology*
D015065:17-Hydroxycorticosteroids; D011506:Proteins; D011965:Receptors, Glucocorticoid; D011987:Receptors, Steroid; D003609:Dactinomycin; D011691:Puromycin; D004247:DNA; D003513:Cycloheximide; D014222:Triamcinolone Acetonide; D003350:Cortodoxone