@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{PfeifferHanackKoppetal.1990, author = {Pfeiffer, A. and Hanack, C. and Kopp, R. and Tacke, R. and Moser, U. and Mutschler, E. and Lambrecht, G. and Herawi, M.}, title = {Human Gastric Mucosa Expresses Glandular M3 Subtype of Muscarinic Receptors}, series = {Digestive Diseases and Sciences}, volume = {35}, journal = {Digestive Diseases and Sciences}, number = {12}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-128286}, pages = {1468-1472}, year = {1990}, abstract = {Five subtypes of muscarinic receptors have been distinguished by pharmacological and molecular biological methods. This report characterizes the muscarinic subtype present in human gastric mucosa by radioligand binding studies. The receptor density was 27 ± 6 fmol/mg protein and the tritiated ligand N-methylscopolamine had an affinity of (Kn) 0.39 ± 0.08 nM (n = 11). The M1 receptor selective antagonist pirenzepine and the M2 receptor selective ligand AF-DX 116 had low affinities of 148 ± 32 nM (n = 13) and 4043 ± 1011 nM (n = 3) K n , respectively. The glandular M3 antagonists hexahydrosiladifenidol and silahexocyclium had high affinities ofKn 78 ± 23 nM (n = 5) and 5.6 ± 1.8 nM (n = 3). The agonist carbachol interacted with a single low-affinity site and binding was insensitive to modulation by guanine nucleotides. Antagonist and agonist binding studies thus showed an affinity profile typical of M3 receptors of the glandular type.}, language = {en} } @article{TackeBentlageSheldricketal.1982, author = {Tacke, R. and Bentlage, A. and Sheldrick, W. S. and Ernst, L. and Towart, R. and Stoepel, K.}, title = {Sila-Pharmaka, 24. Mitt. [1]. Sila-Analoga von Nifedipin-{\"a}hnlichen 4-Aryl-2.6-dimethyl-1.4-dihydropyridin- 3.5-dicarbons{\"a}ure-dialkylestern, II.}, series = {Zeitschrift f{\"u}r Naturforschung B}, volume = {37}, journal = {Zeitschrift f{\"u}r Naturforschung B}, number = {4}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-128381}, pages = {443-450}, year = {1982}, abstract = {In the course of systematic studies on sila-substituted drugs the nifedipine-like 1.4-dihydropyridine derivatives 4a, 4b and 4c were prepared and investigated with respect to sila-substitution effects. By X-ray diffraction analyses 4a, 4b and 4c were found to be isostructural. The C/Si-analogues exhibit similar spasmolytic activities (in vitro, guinea pig ileum), comparable with that of nifedipine. However, the compounds differ substantially in their in vivo activity, as measured by the antihypertensive effect on the renal-hypertensive rat. The experimental results are discussed with respect to the carbon/silicon exchange.}, language = {de} } @article{TackeStreckerSheldricketal.1980, author = {Tacke, Reinhold and Strecker, M. and Sheldrick, W. S. and Ernst, L. and Heeg, E. and Berndt, B. and Knapstein, C.-M. and Niedner, R.}, title = {Sila-Pridinol und Pridinol: Darstellung und Eigenschaften sowie Strukturen im kristallinen und gel{\"o}sten Zustand}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-63654}, year = {1980}, abstract = {Sila-Pridinol (2 b), ein Sila-Analogon des Anticholinergicums Pridinol (2a), wurde auf zwei verschiedenen Wegen dargestellt. Die Kristall- und Molek{\"u}lstrukturen von 2 a und 2 b wurden r{\"o}ntgenstrukturanalytisch bestimmt. 2a bildet im festen Zustand intramolekulare Wasserstoffbr{\"u}ckenbindungen aus, w{\"a}hrend sich in kristallinem 2 b zentrosymmetrische, durch intermolekulare H-Br{\"u}ckenbindungen verkn{\"u}pfte cyclische Dimere finden. IR- und \8^1\)H-NMR-spektroskopische sowie kryoskopische Untersuchungen ergaben Informationen {\"u}ber die Strukturen von 2a und 2 b in verschiedenen L{\"o}sungsmitteln. - Die pharmakologischen und toxikologischen Eigen" schaften von 2a und 2b wurden unter dem Gesichtspunkt bekannter Struktur-Wirkungs-Beziehungen vergleichend untersucht. 2 b erwies sich als ein etwa f{\"u}nfmal so starkes Anticholincrgicum wie 2a.}, subject = {Anorganische Chemie}, language = {de} } @article{TackeZimonyiHegeduesStreckeretal.1980, author = {Tacke, Reinhold and Zimonyi-Heged{\"u}s, E. and Strecker, M. and Heeg, E. and Berndt, B. and Langner, R.}, title = {Sila-Analogon des Tiemoniumiodids}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-63669}, year = {1980}, abstract = {Sila-Tiemoniumiodid (16b), ein Sila-Analogon des Anticholinergicums Tiemoniumiodid (16a), und das Sila-Analogon 14b der entsprechenden Tiemonium-Base 14a wurden erstmalig synthetisiert.14b und 16b sowie die Vorstufen 10-13 und 15 wurden in ihren physikalischen und chemischen Eigenschaften charakterisiert und in ihrer Struktur durch Elementaranalysen sowie \(^1\)H-NMR- und Massenspektren sichergestellt. Die spasmolytischen Eigenschaften der Paare 14a/14b und 16a/16b wurden am isolierten Meerschweinchendarm vergleichend untersucht.}, subject = {Anorganische Chemie}, language = {de} } @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{TackePikiesLinohetal.1987, author = {Tacke, Reinhold and Pikies, J. and Linoh, H. and Rohr-Aehle, R. and G{\"o}nne, S.}, title = {Sila-Procyclidin: Eine neue Synthese sowie Untersuchungen zur peripheren und zentralen anticholinergen Wirkung}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-63815}, year = {1987}, abstract = {Sila-Procyclidin (1 b) sowie dessen Derivate 2b (Sila-Tribexyphenidyl), 3b und 4b (Sila-Cycrimin) wurden - ausgehend von Cl\(_3\)SiCH\(_2\)Cl - durch eine neue, sechsstufige Synthese mit einer Gesamtausbeute von 16 (lb), t9 (2b), 8 (3b) bzw. 7\% (4b) dar· gestellt. - Vergleichende in-vivo-Untcrsuchungen (Maus, per-osApplikation) hinsichtlich der peripheren und zentralen auticholincrgen Wirkung haben gezeigt, daß die Silicium-Verbindung 1 b dem Kohlenstoff-Analogon Ia (Procyclidin) {\"u}berlegen ist.}, subject = {Anorganische Chemie}, language = {de} } @article{SargeCammengaBeckeretal.1988, author = {Sarge, S. and Cammenga, H. K. and Becker, B. and Rohr-Aehle, R. and Tacke, Reinhold}, title = {Energetic and kinetic investigation of thermally induced molecular rearrangements of esters of (hydroxymethyl)hydridosilanes by DSC}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-63850}, year = {1988}, abstract = {No abstract available}, subject = {Anorganische Chemie}, language = {en} } @article{LambrechtFeifelWagnerRoederetal.1989, author = {Lambrecht, G. and Feifel, R. and Wagner-R{\"o}der, M. and Strohmann, C. and Zilch, H. and Tacke, Reinhold and Waelbroeck, M. and Christophe, J. and Boddeke, H. and Mutschler, E.}, title = {Affinity profiles of hexahydro-sila-difenidol analogues at muscarinic receptor subtypes}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-63979}, year = {1989}, abstract = {In an attempt to assess the structural requirements of hexahydro-sila-difenidol for potency and selectivity, a series of analogues modified in the amino group and the phenyl ring were investigated for their affinity to muscarinic M1- (rabbit vas deferens), Mr (guinea-pig atria) and Mr (guinea-pig ileum) receptors. All compounds were competitive antagonists in the three tissues. Their affinities to the three muscarinic receptor subtypes differed by more than two orders of magnitude and the observed receptor selectivities were not associated with high affinity. The pyrrolidino and hexamethyleneimino analogues, compounds substituted in the phenylring with a methoxy group or a chlorine atom as weil as p-fluoro-hexahydro-difenidol displayed the same affinity profile as the parent compound, hexahydro-sila-difenidol: M1 = M3 > M2 • A different selectivity patternwas observed for p-fluoro-hexahydro-sila-difenidol: M3 > M1 > M2 • This compound exhibited its highest affinity for M3-receptors in guinea-pig ileum (pA 2 = 7.84), intermediate affinity for M1-receptors in rabbit vas deferens (pA 2 = 6.68) and lowest affinity for the Mrreceptors in guinea-pig atria (pA 2 = 6.01). This receptor selectivity profile of p-fluoro-hexahydro-sila-difenidol was confirmed in ganglia (M1), atria (M2 ) and ileum (M 3 ) of the rat. Furthermore, dose ratios obtained with either pirenzepine (Mt) or hexahydrosila- difenidol (M2 and M3) and the p-fluoro analogue used in combination suggested that the antagonism was additive, implying mutual competition with a single population of muscarinic receptor subtypes. These results indicate that p-fluoro-hexahydro-sila-difenidol represents a valuable tool for characterization of muscarinic receptor subtypes.}, subject = {Anorganische Chemie}, language = {en} } @article{KoppLambrechtMutschleretal.1989, author = {Kopp, R. and Lambrecht, G. and Mutschler, E. and Moser, U. and Tacke, Reinhold and Pfeiffer, A.}, title = {Human HT-29 colon carcinoma cells contain mucarinic M\(_3\) receptors coupled to phosphoinositide metabolism}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-63989}, year = {1989}, abstract = {Five different musearlnie receptor subtypes ean be distinguished by the differenees in their amino aeid sequence, the eoupled signal transduetion system, pharmaeologieal binding properties and aetivation of ionie fluxes. The present study served to eharaeterize the binding profile of musearlnie receptors in human eolon eareinoma eells (HT-29) using seleetive musearlnie antagonists. The affinities of the compounds were eompared with their poteney to inhibit cholinergieally-aetivated phosphoinositide metabolism. Pirenzepine displaced [\(^3\)H]N-methyl-scopolamine binding and inhibited inositolphosphate (IP) release with potencies typieal of those of non-M\(_1\) receptors. The M\(_3\) subtype-selective antagonists sila-hexocyelium and hexahydro-sila-difenidol bad high affinity to the musearlnie reeeptors in HT-29 cells (K0 = 3.1 nM and 27 nM, respectively) and inhibited IP release at nanomolar concentrations. The M\(_2\) receptor antagonists, AF-DX 116 and methoctramine, had low antimusearinic poteneies. Our results demonstrate that HT-29 human colon earcinoma cells contain an apparently pure population of M\(_3\) receptors. These cells could serve as a model system for further investigations coneerning regulatory and signal transduction mechanisms associated with glandular muscarinic M\(_3\) receptors.}, subject = {Anorganische Chemie}, language = {en} } @article{FeifelWagnerRoederStrohmannetal.1990, author = {Feifel, R. and Wagner-R{\"o}der, M. and Strohmann, C. and Tacke, Reinhold and Waelbroeck, M. and Christophe, J. and Mutschler, E. and Lambrecht, G.}, title = {Stereoselective inhibition of muscarinic receptor subtypes by the enantiomers of hexahydro-difenidol and acetylenic analogues}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-64002}, year = {1990}, abstract = {1 Tbc affinities of the (R)- and (S)-enantiomers of hexahydro-difenidol (1) and its acetylenie analogues hexbutinol (2), hexbutinol methiodide (3) and p-fluoro-hexbutinol (4) (stereochemieal purity > 99.8\%) for musearlnie receptors in rabbit vas deferens (M1), guinea-pig atria (M2) and guinea-pig ileum (M3) were measured by dose-ratio experiments. 2 The (R)-enantiomers consistently showed higher aßinities than the (S)-isomers. The stereosclectivity ratios [(R)/(S)] wcrc greatest with thc enantiomers of 1 (vas deferens: 550; ilcum: 191; atria: 17) and least with thosc ofthc p-Fluoro-analogue 4 (vas defercns: 34; ileum: 8.5; atria: 1.7). 3 The enantiomerie potency ratios for compounds 1-4 were highest in rabbit vas deferens, intermediate in guinea-pig ileum and much less in guinea-pig atria. Thus, these ratios may serve as a predietor of muscarinic receptor subtype identity. 4 (S)-p-Fluoro-hexbutinol [(S)-4] showed a novel receptor selectivity profile with preference for M\(_3\) receptors: M\(_3\) > M\(_2\) \(\geq\) M\(_1\)• 5 These results do not conform to Pfeiffer's rule that aetivity differences between enantiomers are greater with more potent compounds.}, subject = {Anorganische Chemie}, language = {en} } @article{DoerjeWessLambrechtetal.1991, author = {D{\"o}rje, F. and Wess, J. and Lambrecht, G. and Tacke, Reinhold and Mutschler, E. and Brann, M. R.}, title = {Antagonist binding profiles of five cloned human muscarinic receptor subtypes}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-64113}, year = {1991}, abstract = {A variety of muscarinic antagonists are currently used as tools to pharmacologically subclassify muscarinic receptors into M\(_1\), M\(_2\) and M\(_3\) subtypes. ln the present study I we have determined the affinity proflies of several of these antagonists at five cloned human muscarinic receptors (m1-m5) stably expressed in Chinesehamster ovary cells (CHO-K1). At all five receptorsl the (R)-enantiomers of trihexyphenidyl and hexbutinol displayed considerably higher affinities (up to 525-fold) than their corresponding (S)-isomers. The stereoselectivity ratios [inhibition constant( S)/inhibition constant(R)] for both pairs of enantiomers were lowest at m2 receptors, suggesting that less stringent configurational demands are made by this receptor subtype. The "M\(_1\)-selective" antagonist (R)-trihexyphenidyl displayed high affinities for m1 and m4 receptors. The "M\(_2\)-selective" antagonists himbacinel (±}-5, 11-dihydro-11-1[(2-[(dipropylamino)methyl]-1- piperidinyllethyl)amino]carbonyii-6H-pyrido(213-b)(1 ~4)benzodiazepine- 6-one (AF-DX 384)1 11-(14-[4-(diethylamino)butyl)-1-piperidinyll acetyl)-5~ 11-dihydro-6H-pyrido(2~3-b) (1~4)benzodiazepine-6-one (AQ-RA 741) and (+K11-(12-[(diethylamino)methyl]-1-piperidinyll acetyl)-5~ 11-di-hydro-6H-pyrido(2~3-b)(1,4)benzodiazepine-6-one (AF-OX 250; the (+)-enantiomer of AF-DX 116] exhibited high affinities for m2 and m41 intermediate affinities for m1 and m3 and low affinities for m5 receptors. This selectivity profile was most prominent for AQ-RA 7 41 I which displayed 195- and 129-fold higher affinities for m2 and m4 receptors than for mS receptors. The "M\(_3\)-selective" antagonist (±)-p-fluoro-hexahydro-sila-difenidol hydrochloride (pFHHsiD) exhibited high affinity for m1 I m3 and m4 receptors. 4-diphenylacetoxy-N-methylpiperidine methiodide (4-DAMP) bound with up to 7 -fold higher affinities to m1 I m31 m4 and m5 receptors than to m2 receptors. Although none of the tested antagonists showed more than 2-fold selectivity for one subtype over all other subtypes, each receptor displayed a unique antagonist binding profile.}, subject = {Anorganische Chemie}, language = {en} } @article{TackeWiesenbergerBeckeretal.1992, author = {Tacke, Reinhold and Wiesenberger, F. and Becker, B. and Rohr-Aehle, R. and Schneider, P. B. and Ulbrich, U. and Sarge, S. M. and Cammenga, H. K. and Koslowski, T. and Niessen, W. von}, title = {Ester von (Hydroxymethyl)diorganylsilanen: Synthese und thermisch induzierte Umlagerung}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-64188}, year = {1992}, abstract = {Twenty silanes of the type R\(^1\)R\(^2\)Si(H)CH\(_2\)OR\(^3\) (A) were syn- and entropy of activation) of these reactions were studied by thesized {R\(^1\), R\(^2\) = Me, Ph, 1-naphthyl, PhCH\(_2\), Me\(_3\)SiCH\(_2\); OR\(^3\) means of d{\"u}ferential scanning calorimetry (DSC). In addition, = OC(O)Me, OC(O)Ph, OC(O)CF\(_3\) , OS(0)\(_2\)CF\(_3\), OP(O)Ph\(_2\), the kinetics of all reactions were investigated by 1H-NMR OC(O)Cl, and studied for their thermal behaviour. The silanes spectroscopy. The transition state of the rearrangement was A undergo a thermally induced rearrangement to give the investigated by an ab initio study based on the model comcorresponding silanes R\(^1\)R\(^2\)Si(OR\(^3\))Me (B). For compounds with pound H\(_3\)SiCH\(_2\)OC(O)H (-> MeH\(_2\)SiOC(O)H]. The theoretical OR3 = OC(O)Cl, an additional decarboxylation takes place to data and the experimentally obtained energetic and kinetic yield the chlorosilanes R1R2Si(Cl)Me. Except for the deriva- data are discussed in terms of mechanistic aspects of the retives with OR\(^3\) = OC(O)Cl, the energetic (reaction enthalpy) arrangement reaction A -> B. and kinetic data (reaction order, frequency factor, enthalpy ...}, subject = {Anorganische Chemie}, language = {de} } @article{BungardtVockertFeifeletal.1992, author = {Bungardt, E. and Vockert, E. and Feifel, R. and Moser, U. and Tacke, Reinhold and Mutschler, E. and Lambrecht, G. and Suprenant, A.}, title = {Characterization of muscarinic receptors mediating vasodilation in guinea-pig ileum submucosal arterioles by the use of computer-assisted videomicroscopy}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-64206}, year = {1992}, abstract = {Muscarinic receptors of rcsistance vessels (submucosal artcrioles, outside diametcr 50-75 J,Lm) from the guinea-pig small intestinc were invcstigatcd in vitro using a computcr-assisted vidcomicroscopy system (Diamtrak <~t ). The muscarinic receptor which mediates vasodilation of prccontractcd [U-46619 (300 nM) or (- )-noradrcnaline (1 0 J.L M)] artcriolcs was characterized with scveral muscarinic agonists and subtypc-sclectivc antagonists. Thc following agonists all produccd cquivalent maximum vasodilation (given in rank ordcr of potency): acctylcholinc = arccaidinc propargyl cstcr (APE) > oxotremorine = ( ± )-muscarinc = ( ± )-mcthacholinc > carbachol > 4-[[N-{4-chlorophenyl)carbamoyl]oxy]-2-hutynyltrimcthylammonium iodide (4-CI-McN-A- 343). 4-([N-(3-ChlorophcnyD-carbamoyl)oxy]-2-butynyltrimcthylammonium chloride (McN-A-343) and N-ethyl-guvacinc propargyl ester (NEN-APE) produccd minimal or no artcriolar vasodilation. Thc muscarinic antagonists pircnzcpinc, ( ± )-5,11-dihydro-11- [[[2-[2-((dipropylamino)methyl}-1-pipcridinyl]ethyl]amino ]-carbonyi]-6H-pyrido(2,3-h)( 1 ,4)-benzodiazcpin-6-onc (AF-DX 384 ), 11- [[ 4-[4-(dicthylamino)butyl]-1-piperidinyl]acetyl]-5, ll-dihydro-6H-pyrido(2.3-h)( 1,4 )-bcnzodiazepin-6-onc (AQ-RA 741 ), p-fluorohexahydro- sila-difcnidol (p-F-HHSiD), 4-diphcnylacetoxy-N-methylpipcridine mcthiodidc (4-DAMP) and (R)- and (S)hexahydro- difcnidol [(R)-HHD, (S)-HHD] shifted thc muscarinc, mcthacholinc or carbachol dosc-rcsponsc curve to the right in a compctitive manner. Schildanalysis of the data yicldcd pA\(_2\) valucs for pircnzcpinc (6.74/6.9), AF-DX 384 (6.72), AQ-RA 741 (6.58), p-F-HHSiD (7.53/7.57), 4-DAMP (9.06), (R)-HHD (7.88/8.32) and (S)-HHD (5.52/5.88). Thus, it can he concluded that submucosal arteriolcs posscss only the M\(_3\) functional muscarinic reccptor, the activation of which causcs hlood vcsscl dilation. The preparation dcscribcd is considcrcd to be a valuable now bioassay for pharmacological investigations of drug actions at muscarinic receptors in the peripheral vascular system.}, subject = {Anorganische Chemie}, language = {en} } @article{TackeNiednerFrohneckeetal.1980, author = {Tacke, Reinhold and Niedner, R. and Frohnecke, J. and Ernst, L. and Sheldrick, W. S.}, title = {Darstellung und Eigenschaften potentiell curarewirksamer Silicium-Verbindungen, II}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-63670}, year = {1980}, abstract = {Die potentiell curarewirksamen Silicium-Verbindungen Sa, Sc, Sd, Sg, Sh und 9a-9d wurden dargestellt. \(^1\)H-NMR-spektroskopische Untersuchungen ergaben Informationen {\"u}ber die Konformationen von 5 a- Sc in L{\"o}sung. Die Kristall- und Molek{\"u}lstruktur von 5 c wurde r{\"o}ntgenstrukturanalytisch bestimmt. Die muskelrelaxierenden Eigenschaften von S a- 5 h und 9 a-9 d wurden vergleichend an der Maus (i.v., LD50-Werte) untersucht. Die ermittelten Struktur-WirkungsBeziehungen werden in Hinblick auf die unterschiedlichen kovalenten Radien des Kohlenstoffund Siliciumatoms und die hieraus resultierenden N ... N-Abst{\"a}nde diskutiert.}, subject = {Anorganische Chemie}, language = {de} } @article{TackeStreckerNiedner1981, author = {Tacke, Reinhold and Strecker, M. and Niedner, R.}, title = {Cholinesterase-hemmende Organophosphors{\"a}ureester und ihre Sila-Analoga}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-63689}, year = {1981}, abstract = {Die Organophosphors{\"a}ureester la-4a und ihre Sila-Analoga lb-4b des Typs R\(^1\)R\(^2\)P(O)( p-OC\(_6\)H\(_4\)ElMe\(_3\)) (EI = C, Si) wurden synthetisiert. Die Kohlenstoff-Verbindungen 1 a- 4a zeigen hinsichtlich ihrer Anticholinesterase-Aktivit{\"a}t die gleichen Struktur-Wirkungs-Beziehungen wie die Silicium-Verbindungen 1 b- 4 b. Letztere sind jeweils wirksamer als die entsprechenden C-Analoga.}, subject = {Anorganische Chemie}, language = {de} } @article{TackeFrohneckeNiedner1982, author = {Tacke, Reinhold and Frohnecke, J. and Niedner, R.}, title = {Darstellung und Eigenschaften potentiell curarewirksamer Silicium-Verbindungen, IV}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-63711}, year = {1982}, abstract = {Die Synthese der Organosilicium· Verbindungen 3 a- d wird erstmalig beschrieben. Sie wurden durch ihre physikalischen, chemischen und pharmakologischen Eigenschaften charakterisiert. Ja- d wirken als uKurzzeit-Muskelrelaxantien", deren Entgiftung durch Hydrolyse der Si- OeBindungen (Sollbruchstellen) erfolgt.}, subject = {Anorganische Chemie}, language = {de} } @article{LambrechtFeifelForthetal.1988, author = {Lambrecht, G. and Feifel, R. and Forth, B. and Strohmann, C. and Tacke, Reinhold and Mutschler, E.}, title = {p-Fluoro-hexahydro-sila-difenidol: the first M\(_{2\beta}\)-selective muscarinic antagonist}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-63872}, year = {1988}, abstract = {No abstract available}, subject = {Anorganische Chemie}, language = {en} } @article{TackeRohrAehle1988, author = {Tacke, Reinhold and Rohr-Aehle, R.}, title = {Ester des (Hydroxymethyl)[(trimethylsilyl)methyl]silans: Synthese und thermisch induzierte Umlagerung}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-63889}, year = {1988}, abstract = {Die Synthese des (Hydroxymethyl)[(trimethylsilyl)methyl]silans (3) sowie des hiervon abzuleitenden Acetats 4 und Chlorformiats 6 wird beschrieben. 4 und 6 unterliegen einer thermisch induzierten Umwandlung zu den difunktionellen Silanen 5 bzw. 8. Die Umwandlungen 4 -> 5 und 6 -> 8 erfolgen gem{\"a}ß einer Kinetik 1. Ordnung mit Halbwertszeiten von 10.0 bzw. 3.6 h (135 ° C, in C\(_6\)D\(_6\)).}, subject = {Anorganische Chemie}, language = {de} } @article{PfeifferRochlitzNoelkeetal.1990, author = {Pfeiffer, A. and Rochlitz, H. and Noelke, B. and Tacke, R. and Moser, U. and Mutschler, E. and Lambrecht, G.}, title = {Muscarinic receptors mediating acid secretion in isolated rat gastric parietal cells are of M3 type}, series = {Gastroenterology}, volume = {98}, journal = {Gastroenterology}, number = {1}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-128337}, pages = {218-222}, year = {1990}, abstract = {Five subtypes of muscarinic receptors have been identified by pharmacological and molecular biological methods. The muscarinic receptor subtype mediating acid secretion at the level of the parietal cell was unknown. Therefore, this study was performed to characterize muscarinic receptors on rat gastric parietal cells using the 3 subtype-selective antagonists hexahydrosiladifenidol and silahexocyclium, which have high affinity for glandular M3 subtypes, and AF-DX 116, which has high affinity to cardiac M2 receptors. The affinity of these antagonists was determined by radioligand binding experiments. In addition, their inhibitory potency on carbachol-stimulated inositol phosphate production was investigated. Inhibition of carbachol-stimulated aminopyrine uptake was used as an indirect measure of proton production. Both M3 antagonists, hexahydrosiladifenidol and silahexocyclium, had nanomolar affinities for parietal cell muscarinic receptors and potently antagonized inositol phosphate production with nanomolar Ki values. Silahexocyclium similarly antagonized aminopyrine accumulation while hexahydrosiladifenidol behaved as a noncompetitive antagonist. AF-DX 116 was a low-affinity ligand and a weak competitive antagonist at parietal-cell muscarinic receptors. It was concluded that muscarinic M3 receptors mediate acid secretion probably by activation of the phosphoinositide second messenger system in rat gastric parietal cells.}, language = {en} }