Dieter Waumans
Katholieke Universiteit Leuven
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Publication
Featured researches published by Dieter Waumans.
Biochemical Pharmacology | 2001
Chris Ulens; Lanning Baker; Anna Ratka; Dieter Waumans; Jan Tytgat
Using heterologous expression in Xenopus laevis oocytes, we compared the potencies of morphine, morphine-6beta-glucuronide (M6G), and morphine-3-glucuronide (M3G) for cloned human mu- (hMOR), kappa- (hKOR), and delta-opioid receptors (hDOR). Each receptor subtype was individually co-expressed with heteromultimeric G-protein coupled inwardly rectifying K(+) (GIRK) channels, consisting of GIRK1 and GIRK2 subunits, and RGS4, a regulator of G-protein signaling. The two-microelectrode voltage clamp technique was used to measure the opioid receptor-activated GIRK1/GIRK2 channel responses. Compared with morphine, M6G had higher potency at the hMOR, lower potency at the hKOR, and similar potency at the hDOR, while M3G showed a 1000-fold lower and non-selective potency via opioid receptors. In contrast to naloxone, M3G did not antagonize the effects of morphine at the hMOR. We also investigated whether Trp318 and His319 provide the molecular basis for mu/delta selectivity and mu/kappa selectivity of morphinan alkaloids by mutating these residues to their corresponding residues in kappa- and delta-opioid receptors. A single-point mutation (W318L) on hMOR completely conferred delta-like potency for morphine and M6G on the mutant mu-receptor. Double mutation at Trp318 and His319 positions (Trp318Y/His319Y) only partially conferred kappa-like potency for morphine and M6G; the decrease in potency for M6G was significantly larger than for morphine. The results of our study show that both M6G and M3G are opioid receptor agonists with different potencies and that the potency of morphinan receptor ligands can be changed by selective mutations of hMOR at the Trp318 and His319 positions.
Forensic Science International | 2004
Dieter Waumans; Bas Hermans; Noël Bruneel; Jan Tytgat
Archive | 2013
Eva Cuypers; Marieke De Boeck; Anja Ledinek; Ruth Verplaetse; Dieter Waumans; Sara Loix; Arne Bonneure; Wim Van de Voorde; Jan Tytgat
Archive | 2012
E. Rosier; D. Maes; Dieter Waumans; Ruth Verplaetse; Eva Cuypers; T. Ivaneanu; Jan Tytgat
toxichem | 2010
Ruth Verplaetse; Eva Cuypers; C. Silvestre; Dieter Waumans; Jan Tytgat
Archive | 2009
Ruth Verplaetse; Dieter Waumans; Noël Bruneel; Eva Cuypers; J. de Winne; B. Smedts; W. Van de Voorde; Jan Tytgat
Archive | 2007
Ruth Verplaetse; Dieter Waumans; Noël Bruneel; Eva Cuypers; J. de Winne; B. Smedts; W. Van de Voorde; Jan Tytgat
Archive | 2007
Ruth Verplaetse; Dieter Waumans; Noël Bruneel; Suzanne Toppet; Wim Dehaen; Jan Tytgat
Archive | 2004
Dieter Waumans; Noël Bruneel; Jan Tytgat
Farmaceutisch Tijdschrift voor Belgie | 2004
Frank Bosmans; Dieter Waumans; Bas Hermans; Noël Bruneel; Jan Tytgat