PMID- 2387251 OWN - NLM STAT- MEDLINE DCOM- 19900921 LR - 20131121 IS - 0013-7227 (Print) IS - 0013-7227 (Linking) VI - 127 IP - 3 DP - 1990 Sep TI - Expression of neural 5 alpha-reductase messenger ribonucleic acid: comparison to 5 alpha-reductase activity during prenatal development in the rat. PG - 1121-8 AB - The present study was designed to characterize the developmental pattern of 5 alpha-reductase messenger RNA (mRNA) levels and enzyme activity in intact medial basal hypothalamic (MBH) and preoptic area (POA) tissue fragments of rats during fetal development. 5 alpha-Reductase activity was determined using [3H]testosterone as the substrate and quantifying, by TLC, the radiolabeled 5 alpha-reduced metabolites (dihydrotestosterone [DHT] and 5 alpha-androstane-3 alpha,17 beta-diol). Confirmation of the identity of the [3H]5 alpha-DHT formed was demonstrated by recrystallization of the derivatized DHT to constant specific activity. Under saturating substrate conditions (1.7 microM testosterone), there were no significant sex differences (male vs. female) detected in neural 5 alpha-reductase during prenatal, perinatal, or neonatal development. 5 alpha-Reductase activity was low but detectable at gestational day (GD) 15 (approximately 10 pmol/h.mg protein), increased over 3-fold to peak levels at GD 18, and then declined to moderate levels at GD 22 (approximately 22 pmol/h.mg protein) and 4 days after birth (approximately 17 pmol/h.mg protein). In addition, the developmental pattern of 5 alpha-reductase mRNA expression in fetal MBH-POA tissue was determined, by RNA blot hybridization, using a complementary DNA encoding the rat 5 alpha-reductase enzyme. A single mRNA species was detected at 2.5 kilobase in MBH-POA tissue, which is similar in size to adult rat liver and prostate 5 alpha-reductase mRNA. At GD 15, 5 alpha-reductase mRNA was clearly detectable; the abundance increased on GD 17, remained at maximal levels at GDs 18, 19, and 20, and then decreased to moderate levels on GD 22. A correlation calculated between the normalized 5 alpha-reductase mRNA levels and enzyme activities revealed a strong correspondence between mRNA abundance and enzyme activity values during prenatal development, r = 0.80, P = 0.056. These findings indicate that neural 5 alpha-reductase activity may be developmentally regulated, and that the changes in 5 alpha-reductase activity in MBH-POA tissue during late fetal development are regulated, in part, by the levels of mRNA encoding the 5 alpha-reductase enzyme. FAU - Lephart, E D AU - Lephart ED AD - Cecil H. and Ida Green Center for Reproductive Biology Sciences, University of Texas Southwestern Medical Center, Dallas 75235. FAU - Andersson, S AU - Andersson S FAU - Simpson, E R AU - Simpson ER LA - eng GR - AG 08176/AG/NIA NIH HHS/United States GR - GM 43753/GM/NIGMS NIH HHS/United States PT - Comparative Study PT - Journal Article PT - Research Support, U.S. Gov't, P.H.S. PL - United States TA - Endocrinology JT - Endocrinology JID - 0375040 RN - 0 (RNA, Messenger) RN - 08J2K08A3Y (Dihydrotestosterone) RN - 25126-76-5 (Androstane-3,17-diol) RN - 3XMK78S47O (Testosterone) RN - EC 1.3.99.5 (3-Oxo-5-alpha-Steroid 4-Dehydrogenase) SB - IM MH - 3-Oxo-5-alpha-Steroid 4-Dehydrogenase/*genetics/metabolism MH - Androstane-3,17-diol/metabolism MH - Animals MH - Dihydrotestosterone/metabolism MH - Female MH - *Gene Expression MH - Gestational Age MH - Hypothalamus, Middle/*embryology/enzymology MH - Male MH - Nucleic Acid Hybridization MH - Preoptic Area/*embryology/enzymology MH - RNA, Messenger/*metabolism MH - Rats MH - Testosterone/metabolism EDAT- 1990/09/01 00:00 MHDA- 1990/09/01 00:01 CRDT- 1990/09/01 00:00 PHST- 1990/09/01 00:00 [pubmed] PHST- 1990/09/01 00:01 [medline] PHST- 1990/09/01 00:00 [entrez] AID - 10.1210/endo-127-3-1121 [doi] PST - ppublish SO - Endocrinology. 1990 Sep;127(3):1121-8. doi: 10.1210/endo-127-3-1121.