Steroid receptors in osteoblasts
| Autor: | Bunzo Sato, Keishi Matsumoto, Keiro Ono, Toshiro Yoshioka |
|---|---|
| Rok vydání: | 1980 |
| Předmět: |
Receptors
Steroid medicine.medical_treatment Cell Binding Competitive Promegestone Dexamethasone Steroid medicine Animals Orthopedics and Sports Medicine Binding site Beta (finance) Receptor Osteoblasts Estradiol business.industry Dihydrotestosterone General Medicine Sex hormone receptor Molecular biology Rats medicine.anatomical_structure Collagenase Alkaline phosphatase Surgery business medicine.drug |
| Zdroj: | Clinical orthopaedics and related research. (148) |
| ISSN: | 0009-921X |
| Popis: | Using the whole-cell incubation system at 37 degrees C, the specific bindings for 3H-dexamethasone, 3H-estradiol-17 beta, 3H-dihydrotestosterone and 3H-R5020 were measured in the purified, putative osteoblasts isolated from fetal rat calvaria by collagenase digestion. More than 90% of the purified cells contained intense alkaline phosphatase activity. The specific binding for 3H-dexamethasone with high affinity and low capacity was demonstrated in the isolated osteoblasts. Most of the binding was found in the nuclear fraction, indicating nucler binding of the 3H-dexamethasone-receptor complex. The apparent dissociation constant (Kd) for 3H-dexamethasone was estimated to be 3.3 x 10(-9)M and the number of binding sites was calculated to be 65 fmol/ml (4 x 10(6) cells) or 9,750 binding sites per cell. High salt: sucrose gradient analysis of nuclear extracts revealed a radioactive 4.0 S peak. These results indicate that the purified osteoblasts are among the target cells for glucocorticoids. On the other hand, the specific bindings for 3H-estradiol-17 beta and 3H-dihydrotestosterone were not detectable in the isolated osteoblasts, which suggests that estrogens and androgens act on osteoblasts only indirectly. |
| Databáze: | OpenAIRE |
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