title: Expression and possible role of 20alpha-hydroxysteroid dehydrogenase in the placenta of the goat.
abstract: 20Alpha-hydroxysteroid dehydrogenase (20alpha-HSD) catalyzes the conversion of progesterone to its inactive form 20alpha-dihydroprogesterone (20alpha-OHP). 20Alpha-HSD is expressed in the murine placenta, suggesting a role, yet unidentified, played by this enzyme during the course of pregnancy. To elucidate the possible roles of 20alpha-HSD during pregnancy, 20alpha-HSD gene expression in the placenta was examined by Northern blot analysis, and progestin (progesterone and 20alpha-OHP) concentrations in the maternal and fetal sera and the amniotic fluid were measured by radioimmunoassay in pregnant Shiba goats. The expression of 20alpha-HSD mRNA was observed in the placenta and the intercaruncular part of the uterus during mid to late pregnancy. Analysis by in situ hybridization revealed that 20alpha-HSD mRNA was mainly localized in the endometrial epithelium of the caruncle side of the placenta. Considerable enzyme activity of 20alpha-HSD was also detected in the cytosolic fraction of the placenta and intercaruncular part of the uterus. Although concentrations of progesterone and 20alpha-OHP in the maternal serum showed similar profiles, progesterone levels in the fetal serum stayed extremely low throughout the pregnancy. The 20alpha-OHP concentration in the fetal serum was always higher than that in the maternal serum. In the amniotic fluid, the concentrations of both progesterone and 20alpha-OHP remained at very low levels throughout the pregnancy. These results support the notion that 20alpha-HSD protects the fetus from the cytotoxic effects of progesterone, and thereby maintains the normal development of the fetus.
authors.affiliation: Department of Veterinary Physiology, Veterinary Medical Science, The University of Tokyo, Japan.
authors.forename: Walimuni Samantha Nilanthi
authors.initials: WS
authors.lastname: Jayasekara
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Yonezawa
authors.forename: Maho
authors.initials: M
authors.lastname: Ishida
authors.forename: Keitaro
authors.initials: K
authors.lastname: Yamanouchi
authors.forename: Masugi
authors.initials: M
authors.lastname: Nishihara
mesh_terms: D043607:20-alpha-Hydroxysteroid Dehydrogenase / Q000235:genetics* / Q000378:metabolism*; D000653:Amniotic Fluid / Q000378:metabolism; D000818:Animals; D005260:Female; D005312:Fetal Blood / Q000378:metabolism; D015971:Gene Expression Regulation, Enzymologic; D006041:Goats / Q000502:physiology*; D010920:Placenta / Q000201:enzymology*; D011247:Pregnancy; D011374:Progesterone / Q000097:blood; D012333:RNA, Messenger / Q000032:analysis; D014599:Uterus / Q000201:enzymology
chemical_list: D012333:RNA, Messenger; D011374:Progesterone; D043607:20-alpha-Hydroxysteroid Dehydrogenase