Placenta hydroxysteroid dehydrogenase

Burton, PJ. and Waddell, B.J., Dual function of 1 lP-hydroxysteroid dehydrogenase in placenta Modulating placental glucocorticoid passage and local steroid action, Biol. Reprod., 60, 234, 1999. 

F. Staud, K. Mazancova, I. Miksik, P. Pavek, Z. Fendrich, and J. Pacha. Corticosterone transfer and metabolism in the dually perfused rat placenta Effect of 1 lbeta-hydroxysteroid dehydrogenase type 2. Placenta. 27 171-180 (2006). 

The activity A5-3/3-hydroxysteroid dehydrogenase catalyzes the conversion of pregnenolone to progesterone, the progestational hormone of the placenta and corpus luteum. The product has an absorption maximum at 240 nm, and therefore detection can be readily carried out by UV absorbances near this wavelength. 

Hydroxysteroid dehydrogenases are widely distributed among rat tissue. They have been found in liver, kidney, placenta, and peripheral tissue. Prolonged treatment of mice with cortisol increases the ability of the thymus but not that of spleen and lymph nodes to convert cortisol to cortisone. The 11-hydroxy-ketosteroid dehydrogenase requires NAD or NADP as coenzyme. 

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