Abstract
The concentration of 5α-pregnane-3,20-dione in peripheral blood of pregnant women is higher than that found in blood obtained from nonpregnant women throughout the luteal phase of the ovulatory cycle. The in vitro synthesis of 5α-reduced pregnanes from [ 3H]progesterone by placental tissue was investigated using tissue minces and homogenates in the presence of added nicotinamide-adenine dinucleotide phosphate. The metabolites, [ 3H]5α-pregnane-3,20-dione and [ 3H]3β-hydroxy-5α-pregnan-20-one, were isolated and characterized employing a combination of chromatographic techniques, derivative formation, and crystallization with authentic [ 14C]5α-pregnane-3,20-dione and [ 14C]3β-hydroxy-5α-pregnan-20-one to constant 3H: 14C ratios. In short-term incubations with placenta homogenates, the apparent pH optimum for the synthesis of 5α-pregnane-3,20-dione was 8.8. There was no evidence for the formation of 5β-reduced pregnanes from [ 3H]progesterone by placental tissue. The in vitro metabolism of [ 3H]progesterone by minces of five term placentas, during 1 hour incubations at pH 7.4, was studied. The rate of formation of 5α-pregnane-3,20-dione varied from 109 to 197 pmoles/gm placental tissue/hr.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 611-617 |
| Number of pages | 7 |
| Journal | American Journal of Obstetrics and Gynecology |
| Volume | 133 |
| Issue number | 6 |
| State | Published - 1979 |
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ASJC Scopus subject areas
- Medicine(all)
- Obstetrics and Gynecology
Cite this
5α-Reductase activity in human placenta. / Milewich, L.; Gant, N. F.; Schwarz, B. E.; Chen, G. T.; MacDonald, P. C.
In: American Journal of Obstetrics and Gynecology, Vol. 133, No. 6, 1979, p. 611-617.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - 5α-Reductase activity in human placenta
AU - Milewich, L.
AU - Gant, N. F.
AU - Schwarz, B. E.
AU - Chen, G. T.
AU - MacDonald, P. C.
PY - 1979
Y1 - 1979
N2 - The concentration of 5α-pregnane-3,20-dione in peripheral blood of pregnant women is higher than that found in blood obtained from nonpregnant women throughout the luteal phase of the ovulatory cycle. The in vitro synthesis of 5α-reduced pregnanes from [ 3H]progesterone by placental tissue was investigated using tissue minces and homogenates in the presence of added nicotinamide-adenine dinucleotide phosphate. The metabolites, [ 3H]5α-pregnane-3,20-dione and [ 3H]3β-hydroxy-5α-pregnan-20-one, were isolated and characterized employing a combination of chromatographic techniques, derivative formation, and crystallization with authentic [ 14C]5α-pregnane-3,20-dione and [ 14C]3β-hydroxy-5α-pregnan-20-one to constant 3H: 14C ratios. In short-term incubations with placenta homogenates, the apparent pH optimum for the synthesis of 5α-pregnane-3,20-dione was 8.8. There was no evidence for the formation of 5β-reduced pregnanes from [ 3H]progesterone by placental tissue. The in vitro metabolism of [ 3H]progesterone by minces of five term placentas, during 1 hour incubations at pH 7.4, was studied. The rate of formation of 5α-pregnane-3,20-dione varied from 109 to 197 pmoles/gm placental tissue/hr.
AB - The concentration of 5α-pregnane-3,20-dione in peripheral blood of pregnant women is higher than that found in blood obtained from nonpregnant women throughout the luteal phase of the ovulatory cycle. The in vitro synthesis of 5α-reduced pregnanes from [ 3H]progesterone by placental tissue was investigated using tissue minces and homogenates in the presence of added nicotinamide-adenine dinucleotide phosphate. The metabolites, [ 3H]5α-pregnane-3,20-dione and [ 3H]3β-hydroxy-5α-pregnan-20-one, were isolated and characterized employing a combination of chromatographic techniques, derivative formation, and crystallization with authentic [ 14C]5α-pregnane-3,20-dione and [ 14C]3β-hydroxy-5α-pregnan-20-one to constant 3H: 14C ratios. In short-term incubations with placenta homogenates, the apparent pH optimum for the synthesis of 5α-pregnane-3,20-dione was 8.8. There was no evidence for the formation of 5β-reduced pregnanes from [ 3H]progesterone by placental tissue. The in vitro metabolism of [ 3H]progesterone by minces of five term placentas, during 1 hour incubations at pH 7.4, was studied. The rate of formation of 5α-pregnane-3,20-dione varied from 109 to 197 pmoles/gm placental tissue/hr.
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M3 - Article
C2 - 34324
AN - SCOPUS:0018412221
VL - 133
SP - 611
EP - 617
JO - American Journal of Obstetrics and Gynecology
JF - American Journal of Obstetrics and Gynecology
SN - 0002-9378
IS - 6
ER -