title: 5α-reductase 1 regulates spinal cord testosterone after morphine administration.
abstract: The enzyme 5alpha-reductase 1 (5α-R(1)) that converts testosterone (T) to dihydrotestosterone (DHT) is present in many mammalian tissues including the spinal cord. It is established that morphine administration decreases spinal cord T levels, but the mechanism is still undetermined. Here, we investigated the link between T and the enzyme 5α-R(1) in the spinal cord after morphine administration. For spinal cord steroid extraction, all the animals were killed 30 min, 2 h (acute) and 14 days (chronic) after first drug injection by decapitation. The whole spinal cord was removed and kept frozen at -20°C until T and DHT extraction. The effects of acute and chronic morphine administration on 5α-R(1) expression in the adult male rat spinal cord were evaluated using RT-PCR. Spinal cord T and DHT levels were measured using radioimmunoassay before and after the morphine exposure. Morphine significantly reduced the T concentration after acute and chronic exposure in the spinal cord. In contrast, the 5α-R(1) expression and of course DHT levels increased the following chronic morphine administration. One important reason for the decreasing effect of morphine exposure on the spinal cord T level is due to an increase in the 5α-R(1) levels. We suggest that morphine plays a regulatory role in metabolism of neurosteroids, especially T in the spinal cord via 5α-R(1).
authors.affiliation: Infectious Diseases Department, School of Medicine, Kashan University of Medical Sciences, Kashan, Iran. a_sharif@kums.ac.ir
authors.forename: Alireza
authors.initials: A
authors.lastname: Sharif
authors.forename: Alireza
authors.initials: A
authors.lastname: Shoae-Hassani
authors.forename: Shiva
authors.initials: S
authors.lastname: Sharif
authors.forename: Hamid Reza
authors.initials: HR
authors.lastname: Banafshe
authors.forename: Seyed Abdolreza
authors.initials: SA
authors.lastname: Mortazavi-Tabatabaei
authors.forename: Javad
authors.initials: J
authors.lastname: Verdi
mesh_terms: D013741:3-Oxo-5-alpha-Steroid 4-Dehydrogenase / Q000502:physiology*; D000818:Animals; D013196:Dihydrotestosterone / Q000378:metabolism; D008297:Male; D009020:Morphine / Q000494:pharmacology*; D009294:Narcotics / Q000494:pharmacology*; D018377:Neurotransmitter Agents / Q000378:metabolism; D011863:Radioimmunoassay; D051381:Rats; D017208:Rats, Wistar; D060888:Real-Time Polymerase Chain Reaction; D013116:Spinal Cord / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism*; D013739:Testosterone / Q000378:metabolism*
chemical_list: D009294:Narcotics; D018377:Neurotransmitter Agents; D013196:Dihydrotestosterone; D013739:Testosterone; D009020:Morphine; D013741:3-Oxo-5-alpha-Steroid 4-Dehydrogenase