Implications of Progesterone Metabolism in MA-10 Cells for Accurate Measurement of the Rate of Steroidogenesis
| Autor: | Paul N. Span, Steven R. King, Focko F. G. Rommerts |
|---|---|
| Přispěvatelé: | Developmental Biology |
| Rok vydání: | 2001 |
| Předmět: |
Male
medicine.medical_specialty Time Factors Metabolite medicine.medical_treatment Radioimmunoassay Alpha (ethology) 030209 endocrinology & metabolism Dehydrogenase Biology Antibodies Gas Chromatography-Mass Spectrometry Steroid Mice 03 medical and health sciences chemistry.chemical_compound 0302 clinical medicine Endocrinology 3-Oxo-5-alpha-Steroid 4-Dehydrogenase Internal medicine Tumor Cells Cultured medicine Animals Chromatography High Pressure Liquid Progesterone 030304 developmental biology Chemical Endocrinology 0303 health sciences Hydroxysteroid Dehydrogenases Metabolism 3. Good health Bucladesine chemistry Pregnenolone Dihydrotestosterone Steroids Leydig Cell Tumor medicine.drug |
| Zdroj: | Endocrinology, 142, 12, pp. 5236-42 Endocrinology, 142, 5236-42 Endocrinology, 142(12), 5236-5242. Endocrine Society |
| ISSN: | 1945-7170 0013-7227 |
| DOI: | 10.1210/endo.142.12.8545 |
| Popis: | Item does not contain fulltext In virtually all studies with MA-10 cells, progesterone RIAs have been used to measure steroid synthesis. To test whether progesterone is a stable end product, we investigated the metabolism of added tritiated progesterone and pregnenolone in MA-10 cells over a period of 3 h. Steroids were then extracted, separated by HPLC, and identified by GC/MS. We found that more than 70% of radiolabeled steroids were converted to at least five different metabolites. A major metabolite (40%) was 5 alpha-pregnan-3 alpha or 3 beta-ol-20one. Similar studies, using radiolabeled T, demonstrated conversion to dihydrotestosterone and two forms of 5 alpha-androstane-diols. These data indicate the presence of active 5 alpha-reductase and 3 alpha- and/or 3 beta-hydroxysteroid dehydrogenase activities in MA-10 cells. Because these results suggest that progesterone is an unstable end product, to gauge the level of active metabolism, we incubated cells in the presence of inhibitors of pregnenolone metabolism and assessed pregnenolone levels by RIA. We discovered that basal levels of steroidogenesis in MA-10 cells were considerably higher than previously estimated. Moreover, dibutyryl cAMP-stimulated steroid production was linear over more than 13 h, in contrast to previous findings that measured progesterone levels. Other consequences of inaccurate assessment of steroidogenic activity in MA-10 cells because of the application of the progesterone assay are discussed. |
| Databáze: | OpenAIRE |
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