Endozepine/diazepam binding inhibitor in adrenocortical and Leydig cell lines: Absence of hormonal regulation
| Autor: | A.S. Brown, Peter F. Hall, Vassilios Papadopoulos, M. Shoyab |
|---|---|
| Rok vydání: | 1992 |
| Předmět: |
Male
medicine.medical_specialty Endozepine Trophic hormone Immunoblotting Adrenocorticotropic hormone Biology Sulfur Radioisotopes Biochemistry Mice chemistry.chemical_compound Methionine Endocrinology Adrenocorticotropic Hormone Internal medicine Tumor Cells Cultured medicine Animals Cycloheximide Molecular Biology Diazepam Binding Inhibitor Leydig cell Adrenal cortex Neuropeptides Leydig Cells Luteinizing Hormone Kinetics medicine.anatomical_structure chemistry Adrenal Cortex Cattle Electrophoresis Polyacrylamide Gel Steroids Luteinizing hormone Diazepam binding inhibitor Hormone |
| Zdroj: | Molecular and Cellular Endocrinology. 83:1-9 |
| ISSN: | 0303-7207 |
| DOI: | 10.1016/0303-7207(92)90189-d |
| Popis: | One of the many effects which have been attributed to the peptide endozepine/diazepam binding inhibitor (Ep/DBI) is the stimulation of adrenocortical and testicular Leydig cell mitochondrial steroidogenesis. We have used two cell lines (Y-1 mouse adrenal cell tumour and MA-10 mouse Leydig cell tumour), both of which exhibit hormone stimulated steroid production, to investigate the role of Ep/DBI in acute hormone stimulated steroidogenesis. The time course of incorporation of 35S-translabel into Ep/DBI and its turnover rate when the isotope was removed were examined. Cell samples were extracted and separated on Sep-Pak C18 columns and analysed using sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) and immunoblot analysis followed by fluorography as well as by direct scintillation counting. This allowed us to estimate the in vivo half-life of Ep/DBI and also to investigate the hormonal dependence of the peptide. Data presented here suggest that (i) Ep/DBI levels are not regulated by trophic hormones in these steroidogenic cell lines, and (ii) that the peptide has a relatively long half-life (greater than 3 h), a finding incompatible with suggestions of it having a rapid turnover. Therefore, it seems unlikely that control of Ep/DBI steroidogenic effects is via hormonal modulation of the peptide levels. |
| Databáze: | OpenAIRE |
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