@article{WaelbroeckCamusTastenoyetal.1994, author = {Waelbroeck, M. and Camus, J. and Tastenoy, M. and Feifel, R. and Mutschler, E. and Tacke, R. and Strohmann, C. and Rafeiner, K. and Rodrigues de Miranda, J. F. and Lambrecht, G.}, title = {Binding and functional properties of hexocyclium and sila-hexocyclium derivatives to muscarinic receptor suhtypes}, series = {British Journal of Pharmacology}, volume = {112}, journal = {British Journal of Pharmacology}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-128265}, pages = {505-514}, year = {1994}, abstract = {1 We have compared the binding properties of several hexocyclium and sila-hexocyclium derivatives to muscarinic Ml receptors (in rat brain, human neuroblastoma (NB-OK I) cells and calf superior cervical ganglia), rat heart M2 receptors, rat pancreas M3 receptors and M4 receptors in rat striatum, with their functional antimuscarinic properties in rabbit vas deferens (Ml/M4-like), guinea-pig atria (M2), and guinea-pig ileum (M3) muscarinic receptors. 2 Si la-substitution (C/Si exchange) of hexocyclium (~ sila-hexocyclium) and demethyl-hexocyclium (~demethyl-sila-hexocyclium) did not significantly affect their affinities for muscarinic receptors. By contrast, sila-substitution of demethoxy-hexocyclium increased its affinity 2 to 3 fold for all the muscarinic receptor subtypes studied. 3 The p-fluoro- and p-chloro-derivatives of sila-hexocyclium had lower affinities than the parent compound at the four receptor subtypes, in binding and pharmacological studies. 4 In binding studies, o-methoxy-sila-hexocyclium (Ml = M4 ~ M3 ~ M2) had a much lower affinity than sila-hexocyclium for the four receptor subtypes, and discriminated the receptor subtypes more poorly than sila-hexocyclium (Ml = M3> M4> M2)' This is in marked contrast with the very clear selectivity of demethoxy-sila-hexocyclium for the prejunctional MtlM4-like heteroreceptors in rabbit vas deferens. 5 The tertiary amines demethyl-hexocyclium, demethyl-sila-hexocyclium and demethyl-o-methoxy-silahexocyclium had 10 to 30 fold lower affinities than the corresponding quaternary ammonium derivatives.}, language = {en} } @article{FeifelRodriguesdeMirandaStrohmannetal.1991, author = {Feifel, R. and Rodrigues de Miranda, J. F. and Strohmann, C. and Tacke, Reinhold and Aasen, A. J. and Mutschler, E. and Lambrecht, G.}, title = {Selective labelling of muscarinic M\(_1\) receptors in calf superior cervical ganglia by [\(^3\)H](\(\pm\))-telenzepine}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-64082}, year = {1991}, abstract = {A method was developed to detennine the affinities of antimuscarinic drugs at M\(_1\) receptors. [\(^3\)H](±)-Telenzepine served as radioligand in crude preparations of calf superior cervical ganglia and showed high affinity for a single receptor population. consisting of M1 receptors (K\(_D\) = 1.12 nM). Kinetic experiments showed monophasic association (k\(_1\) =0.017 min\(^{-1}\) nM\(^{-1}\) ) and dissociation (k\(_1\) = 0.017 min\(^{-1}\) ) kinetics, the half-life of dissociation being 41 min at 37°C. The kinetie K\(_D\) value amounted to 1.00 nM. M\(_1\) affinities for pirenzepine, methoctramine. hexahydro-sila-difenidol and p-fluoro-hexahydro-sila-difenidol detennined in competition experiments were similar to those found in functional studies with MI receptors in rabbit isolated vas deferens. The binding assay was used to deterriline the affinities of the (R) and (S) enantiomers of tertiary (trihexyphenidyl, hexahydro-difenidol. hexbutinol, p-fluoro-hexbutinol) and quatemary musearlnie antagonists (trihexyphenidyl methiodide. hexbutinol methiodide). Comparison of results obtained with the rabbit vas deferens suggested that the ionic environment may influence the affinities.}, subject = {Anorganische Chemie}, language = {en} } @article{RettenmayrRodriguesdeMirandaRijntjesetal.1990, author = {Rettenmayr, N. M. and Rodrigues de Miranda, J. F. and Rijntjes, N. V. M. and Russel, F. G. M. and van Ginneken, C. A. M. and Strohmann, C. and Tacke, Reinhold and Lambrecht, G. and Mutschler, E.}, title = {Pharmacokinetic properties of the antimuscarinic drug [\(^3\)H]-hexahydro-sila-difenidol in the rat}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-64022}, year = {1990}, abstract = {The pharmacokinetics of tritiated hexahydrosila- difenidol ([\(^3\)H]-HHSiD) were examined in rats. Furthermore, the distribution of radioactivity was studied by means of whole body autoradiography. After i. v. administration of 2.9 mg/kg HHSiD plus [\(^3\)H]-HHSiD to anaesthetized rats bearing a catheter implanted in the ductus choledochus and receiving a mannitol infusion, HHSiD was rapidly distributed and metabolized. Only 5\% ofthe radioactivity was recovered in blood after 23 s and 0.4\% after 2.5 h. 64\% of the plasma radioactivity could be extracted with hexane from the samples taken 23 s after administration. 52\% of the radioactivity was eliminated within 2.5 h, 13\% by urinary and 39\% by biliary excretion. Following oral administration of 8.6 mg/kg HHSiD plus [\(^3\)H]-HHSiD there was an absorption of approximately one fourth of the administered radioactivity within 4 h. By means of whole body autoradiography (i. v. injection) as well as by tissue distribution measurement the highest Ievels of radioactivity were found in bile, urine, lung, kidney, adrenals, liver and .pancreas. Thus, after i. v. administration to rats HHSiD is rather quickly distributed, metabolized and excreted. This explains its low antimuscarinic potency in vivo.}, subject = {Anorganische Chemie}, language = {en} }