@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}
}
@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{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}
}