3alpha-hydroxysteroid dehydrogenase messenger RNA transcription in the immature rat ovary in response to an ovulatory dose of gonadotropin
| Autor: | L L, Espey, S, Yoshioka, T, Ujioka, S, Fujii, J S, Richards |
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| Rok vydání: | 2001 |
| Předmět: |
Ovulation
Aldehydes 3-Hydroxysteroid Dehydrogenases DNA Complementary Prostaglandin Antagonists Ovary Ketones 3-alpha-Hydroxysteroid Dehydrogenase (B-Specific) Blotting Northern Rats Prostaglandins Animals Eicosanoids Female RNA Messenger Alprostadil Rats Wistar Fallopian Tubes Gonadotropins In Situ Hybridization |
| Zdroj: | Biology of reproduction. 65(1) |
| ISSN: | 0006-3363 |
| Popis: | The ovulatory process in mammals involves a substantial increase in the metabolism of steroids and eicosanoids in response to a surge in LH or to an injection of hCG into experimental animals. This study provides evidence that the ovulatory stimulus causes induction of the gene for 3alpha-hydroxysteroid dehydrogenase (3alpha-HSD), an enzyme that belongs to several oxidoreductase superfamilies that affect steroid and eicosanoid metabolism. Immature Wistar rats were primed with 10 IU eCG s.c., and 48 h later the 12-h ovulatory process was initiated by 10 IU hCG s.c. Ovarian RNA was extracted at 0, 2, 4, 8, 12, and 24 h after injecting the animals with hCG. The RNA extracts were used for reverse transcription-polymerase chain reaction (PCR) differential display to detect gene expression in the stimulated ovarian tissue. One of the PCR primer sets differentially amplified a cDNA fragment that is 52.3% homologous with a 3alpha-HSD gene in rat liver. Northern analyses revealed that maximum transcription was at 8 h after the animals had been treated with hCG. The Northerns also indicated that the 3alpha-HSD cDNA probe cross-hybridized with as many as six different bands of mRNA on the blots. In situ hybridization localized 3alpha-HSD mRNA in the granulosa and thecal layers of mature follicles and in newly formed corpora lutea at 24 h after the ovulatory stimulus. In conclusion, gene(s) for 3alpha-HSD are transcribed in ovarian follicles in response to an ovulatory dose of gonadotropin. A possible function of the oxidoreductase enzyme that is translated from the 3alpha-HSD mRNA may be to reduce the toxic aldehyde and ketone components of the steroids and eicosanoids that accumulate in the mammalian ovary at the time of ovulation. |
| Databáze: | OpenAIRE |
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