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Inhibition of CYP450scc expression in dioxin-exposed rat Leydig cells.
| Content Provider | Semantic Scholar |
|---|---|
| Author | Lai, Keng Po Wong, Ming-Hung Wong, Chris K. C. |
| Copyright Year | 2005 |
| Abstract | Polychlorinated dibenzo-p-dioxins, such as 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) have been recognized as highly potent developmental and reproductive toxins. We have previously demonstrated effects of TCDD in modulating the expression of rat Sertoli cell secretory products and markers for cell-cell interaction. In this study, we examined the direct biological effects of TCDD in rat Leydig cell primary cultures. Mature rat Leydig cells were purified by Percoll gradient centrifugation and the cell purity was determined by 3beta-hydroxysteroid dehydrogenase (3beta-HSD) staining and a testosterone induction assay. To examine TCDD-induced biological consequences, we measured the changes in the secretion of progesterone and testosterone, as well as transcript levels of some selected steroidogenic enzymes (i.e. StAR, P450scc, 3beta-HSD and CYP17alpha), in TCDD/human chorionic gonadotropin (hCG) co-treated cells. Our results indicated that TCDD (0.2 or 2 ng/ml) treatment significantly suppressed hCG (5 or 10 ng/ml)-induced testosterone secretion. The suppressive effect aligned with a reduction of progesterone secretion (P<0.05), as well as a decrease of P450scc mRNA and protein expression (P<0.05). The mechanistic action of TCDD was found to be via the reduction of cellular cAMP levels in the hCG-treated cells. This observation was further confirmed, as the TCDD-mediated suppressive effect could be reversed by dibutyryl cAMP co-treatment. The data indicate that TCDD can modulate cAMP signaling in rat Leydig cells to affect the process of steroidogenesis. |
| Starting Page | 1 |
| Ending Page | 3 |
| Page Count | 3 |
| File Format | PDF HTM / HTML |
| Alternate Webpage(s) | https://joe.bioscientifica.com/downloadpdf/journals/joe/185/3/1850519.pdf |
| PubMed reference number | 15930178v1 |
| Volume Number | 185 |
| Issue Number | 3 |
| Journal | The Journal of endocrinology |
| Language | English |
| Access Restriction | Open |
| Subject Keyword | 17-Hydroxysteroid Dehydrogenase Deficiency 8-chloro-cyclic adenosine monophosphate Alignment Cell secretion Centrifugation Dioxins Gonadotropins Gradient Hydroxysteroid Dehydrogenases Hydroxysteroids Leukemia, B-Cell Microgram per Liter Percoll Polychlorinated Biphenyls Progesterone Secretion Process Receptors, LH Reproduction Staining method Steroid biosynthesis Testosterone Secretion Process Tetrachlorodibenzodioxin Toxin Transcript amsacrine/cyclophosphamide/etoposide testosterone dehydrogenase [NAD(P)] activity |
| Content Type | Text |
| Resource Type | Article |
