The role of morphinone in the tolerance development to morphine

2014 Fiscal Year Final Research Report

• Project/Area Number: 24659289
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Pain science
• Research Institution: Okayama University
• Principal Investigator: NARIMATSU SHIZUO 岡山大学, 医歯(薬)学総合研究科, 教授 (20113037)
• Co-Investigator(Kenkyū-buntansha): MATSUOKA Junji 岡山大学, 医学部保健学科, 教授 (30332795) ; HANIOKA Nobumitsu 横浜薬科大学, 教授 (70228518)
• Co-Investigator(Renkei-kenkyūsha): YAMANO Shigeru 福岡大学, 薬学部, 教授 (80140755) ; KITA Hideki 福岡大学, 薬学部, 助教 (60341450) ; KUMAMOTO Takuya 武蔵野大学, 薬学部, 教授 (50292678) ; FUNAHASHI Tatsuya 松山大学, 薬学部, 教授 (60343646) ; TANABE Tomotaka 松山大学, 薬学部, 講師 (60532786) ; MASUDA Kazufumi 就実大学, 薬学部, 准教授 (00243486) ; KATAOKA Hiroyuki 就実大学, 薬学部, 教授 (80127555) ; SAITO Keita 就実大学, 薬学部, 講師 (30454854)
• Research Collaborator: MATSUNAGA Hisashi 佐賀県医療センター, 好生館薬剤部, 部長 (10569156) ; IMAMURA Makio 倉敷成人病センター, 診療支援部, 副部長
• Project Period (FY): 2012-04-01 – 2015-03-31
• Keywords: モルヒノン / ヒト尿中代謝物 / 17β-ﾋﾄﾞﾛｷｼｽﾃﾛｲﾄﾞ脱水素酵素 / モルヒネ / エピモルヒネ / μ-受容体-GFP融合タンパク質 / HEK293細胞 / インターナリゼーション

Outline of Final Research Achievements

In this project, we characterized morphinone (MON) as an active metabolite of morphine (M), from various view points. Firstly, considerable amounts of MON were detected in urine samples from cancer patients receiving palliative therapy with M in the LC/MS analysis. Secondly, we characterized the enzyme(s) responsible for MON formation using recombinant rat 17β-hydroxysteroid dehydrogenases type 2 and 6, and kinetic analyses revealed that only type 2 catalyzed the conversion of M to MON in the presence of NAD+ or NADP+. Thirdly, HEK293 cells transformed with a vector in which cDNA encodingμ-receptor-green fluorescence protein (GFP)-fusion proteins were introduced. Addition of M as well as DAMGO, a knownμ-receptor agonist, caused internalization of the fusion proteins in the cell membrane. This HEK 293 cell system may be a useful tool to analyze possible interaction between MON and μ-receptor.

Free Research Field

医歯薬学