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Metabolism of progesterone by placentas from several mammalian species in vitro.
Abstract: 20-alpha-Hydroxysteroid oxidoreductase (20-alpha-HSDH) activity and 20-alpha-dihydroprogesterone concentration (20-alpha-DHP) reach peak values in the human placenta after vaginal delivery. To determine if these findings are unique to the human, we measured 20-alpha-HSDH activity as well as endogenous progesterone (P) and 20-alpha-DHP concentration in the soluble supernatant fraction of placental tissues obtained from rodents (rat, rabbit, guinea pig), ungulates (horse, zebra, giraffe, cow), and primates (squirrel monkey, orangutan, man). P concentration was very low in rodents (mean 0.60 ng/mg protein), increased slightly in ungulates (mean 2.89 ng/mg protein), and reached a maximum value in the human (34.43 ng/mg protein). 20-alpha-DHP concentration had a strong positive correlation (r = 0.93) with P tissue content; it was low in rodents (mean 0.21 ng/mg protein), increased slightly in ungulates (mean 0.79 ng/mg protein), and reached a maximum value in the human (39.53 ng/mg protein). 20-alpha-HSDH activity, however, had a poor correlation with 20-alpha-DHP tissue concentrations: Its lowest value was in the guinea pig (9.34 pmole/mg protein/hour) and the highest was in the horse (3.19 nmole/mg protein/hour). These results indicate that a high level of activity of the P to 20-alpha-DHP pathway with significant tissue accumulation of 20-alpha-DHP is unique to the human placenta and reinforce the possibility of its causing in situ P withdrawal as a part of the overall mechanism of human parturition.
Publication Date: 1979-11-15 PubMed ID: 495682DOI: 10.1016/0002-9378(79)90396-xGoogle Scholar: Lookup The Equine Research Bank provides access to a large database of publicly available scientific literature. Inclusion in the Research Bank does not imply endorsement of study methods or findings by Mad Barn.
- Comparative Study
- Journal Article
- Research Support
- U.S. Gov't
- P.H.S.
Summary
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This research looks at the activity of 20-alpha-Hydroxysteroid oxidoreductase (20-alpha-HSDH) and the concentration of 20-alpha-dihydroprogesterone (20-alpha-DHP) in placental tissues across different mammalian species, with a focus on humans. The results indicate a unique high level of activity of the progesterone to 20-alpha-DHP pathway in humans which may be involved in the process of human childbirth.
Introduction and Goal of the Research
- The investigation focused on the levels of hormones progesterone (P) and 20-alpha-dihydroprogesterone (20-alpha-DHP) in placentas across different mammalian species. Specifically, activity of the enzyme 20-alpha-Hydroxysteroid oxidoreductase (20-alpha-HSDH) was examined, which is involved in the metabolic transformation of progesterone to 20-alpha-DHP.
- The primary goal of the study was to determine if the peak values of 20-alpha-HSDH activity and 20-alpha-DHP concentration in the human placenta after vaginal delivery are unique to humans or similar across different mammalian species.
Study Design and Procedure
- The research involved collecting placental tissues from a diverse range of mammals – rodents (rats, rabbits, guinea pigs), ungulates (horses, zebras, giraffes, cows), and primates (squirrel monkeys, orangutans, humans)
- Measurements for 20-alpha-HSDH activity and endogenous progesterone (P) and 20-alpha-DHP concentrations were made in the soluble supernatant fraction of these placental tissues.
Research Findings
- The results showed that the concentration of progesterone was very low in rodents, increased slightly in ungulates, and reached a maximum value in humans.
- 20-alpha-DHP concentration closely correlated with progesterone tissue content; it was low in rodents, slightly increased in ungulates, and reached a maximum value in humans.
- However, the activity of 20-alpha-HSDH did not correlate well with 20-alpha-DHP tissue concentrations. The lowest value was observed in the guinea pig and the highest in the horse.
- These findings indicated that a high level of activity of the progesterone to 20-alpha-DHP pathway with significant tissue accumulation of 20-alpha-DHP is unique to the human placenta.
Conclusions and Implications
- The study reinforced the possibility that the high activity of the progesterone to 20-alpha-DHP pathway in the human placenta may be responsible for in situ progesterone withdrawal, and could be part of the overall mechanism of human parturition (childbirth).
- This suggests a unique placental function in humans relating to hormone activity and childbirth, which could potentially be a target for further research and therapeutic applications.
Cite This Article
APA
Diaz-Zagoya JC, Wiest WG, Arias F.
(1979).
Metabolism of progesterone by placentas from several mammalian species in vitro.
Am J Obstet Gynecol, 135(6), 809-813.
https://doi.org/10.1016/0002-9378(79)90396-x Publication
Researcher Affiliations
MeSH Terms
- 20-alpha-Dihydroprogesterone / metabolism
- Animals
- Cattle
- Female
- Guinea Pigs
- Horses
- Humans
- Hydroxysteroid Dehydrogenases / metabolism
- In Vitro Techniques
- Mammals
- Perissodactyla
- Placenta / metabolism
- Primates
- Progesterone / analogs & derivatives
- Progesterone / metabolism
- Rabbits
- Rats
- Species Specificity
Citations
This article has been cited 2 times.- Nanjidsuren T, Min KS. The transcription factor Ap-1 regulates monkey 20α-hydroxysteroid dehydrogenase promoter activity in CHO cells. BMC Biotechnol 2014 Jul 30;14:71.
- Ma H, Penning TM. Characterization of homogeneous recombinant rat ovarian 20alpha-hydroxysteroid dehydrogenase: fluorescent properties and inhibition profile. Biochem J 1999 Aug 1;341 ( Pt 3)(Pt 3):853-9.
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