Skip to Main content Skip to Navigation
Journal articles

Endogenous morphine signaling via nitric oxide regulates the expression of CYP2D6 and COMT: autocrine/paracrine feedback inhibition

Abstract : We determined changes in mRNA expression in specific enzymes involved in the biosynthesis of morphine in human white blood cells via microarray. Leukocyte exposure to morphine down-regulated catechol-O-methyl transferase (COMT) and CYP2D6 by approximately 50% compared with control values. The treatment did not alter DOPA decarboxylase and dopamine beta-hydroxylase expression, demonstrating the specificity of morphine actions. The verification of the microarray data was accomplished via real-time Taqman reverse transcriptase polymerase chain reaction (RT-PCR) focused on CYP2D6 and COMT expression in different blood samples treated with morphine. The analysis showed similar changes in the expression of CYP2D6 and COMT mRNA. The expression was reduced by 47 +/- 7% for CYP2D6, substantiating the microarray finding of a 54% reduction. Furthermore, exposure of white blood cells to 10(-6) M S-nitroso-N-acetyl-DL-penicillamine (SNAP), a nitric oxide (NO) donor, reduced the expression of CYP2D6 and COMT. Prior naloxone (10(-6) M) or N-nitro-L-arginine methyl ester (L-NAME) (10(-4) M) addition abrogated morphine's down-regulating activity, demonstrating morphine was initiating its actions via stimulating constitutive NO synthase derived NO release via the mu3 opiate receptor splice variant. In the past we demonstrated that UDP-glucurosyltransferase is involved in metabolizing morphine to morphine 6-glucuronide in adrenal chromaffin cells. In the present study its expression was not found in controls and morphine-treated cells, suggesting that morphine 6-glucuronide may not be synthesized in white blood cells. Taken together, it appears that morphine has the ability to modulate its own synthesis via autocrine and paracrine signaling.
Document type :
Journal articles
Complete list of metadata
Contributor : Yannick Goumon Connect in order to contact the contributor
Submitted on : Wednesday, January 26, 2022 - 12:05:52 PM
Last modification on : Wednesday, February 2, 2022 - 3:38:41 AM
Long-term archiving on: : Wednesday, April 27, 2022 - 6:46:00 PM


 Restricted access
To satisfy the distribution rights of the publisher, the document is embargoed until : jamais

Please log in to resquest access to the document




Kirk Mantione, Patrick Cadet, Wei Zhu, Richard Kream, Melinda Sheehan, et al.. Endogenous morphine signaling via nitric oxide regulates the expression of CYP2D6 and COMT: autocrine/paracrine feedback inhibition. Addiction Biology, Wiley, 2008, 13 (1), pp.118-123. ⟨10.1111/j.1369-1600.2007.00072.x⟩. ⟨inserm-03543887⟩



Record views