TY - JOUR A1 - Kopp, R. A1 - Lambrecht, G. A1 - Mutschler, E. A1 - Moser, U. A1 - Tacke, Reinhold A1 - Pfeiffer, A. T1 - Human HT-29 colon carcinoma cells contain mucarinic M\(_3\) receptors coupled to phosphoinositide metabolism N2 - 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. KW - Anorganische Chemie KW - Muscarinic M3 receptor subtypes KW - HT-29 colon carcinoma cells KW - Phosphatidylinositol metabolism KW - AF-DX 116 Y1 - 1989 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-63989 ER - TY - JOUR A1 - Pfeiffer, A. A1 - Hanack, C. A1 - Kopp, R. A1 - Tacke, R. A1 - Moser, U. A1 - Mutschler, E. A1 - Lambrecht, G. A1 - Herawi, M. T1 - Human Gastric Mucosa Expresses Glandular M3 Subtype of Muscarinic Receptors JF - Digestive Diseases and Sciences N2 - 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. KW - glandular M3 receptor KW - acid secretion KW - muscarinic receptor subtype KW - human gastric mucosa KW - stomach Y1 - 1990 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-128286 VL - 35 IS - 12 ER - TY - JOUR A1 - Pfeiffer, A. A1 - Rochlitz, H. A1 - Noelke, B. A1 - Tacke, R. A1 - Moser, U. A1 - Mutschler, E. A1 - Lambrecht, G. T1 - Muscarinic receptors mediating acid secretion in isolated rat gastric parietal cells are of M3 type JF - Gastroenterology N2 - 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. KW - hexahydrosiladifenidol KW - muscarinic receptors KW - parasympatholytics KW - radioligand assay KW - parasympatholytics/pharmacology KW - gastric acid/secretion KW - animals KW - piperidines/pharmacology KW - piperazines/pharmacology KW - gastric/secretion parietal cells KW - muscarinic/physiology receptors KW - muscarinic/drug effects receptors KW - rats KW - piperidines KW - piperazines KW - silahexocyclium Y1 - 1990 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-128337 VL - 98 IS - 1 ER - TY - JOUR A1 - Brixner, T. A1 - Aeschlimann, M. A1 - Fischer, A. A1 - Geisler, P. A1 - Goetz, S. A1 - Hecht, B. A1 - Huang, J. S. A1 - Keitzl, T. A1 - Kramer, C. A1 - Melchior, P. A1 - Pfeiffer, W. A1 - Razinskas, G. A1 - Rewitz, C. A1 - Schneider, C. A1 - Strüber, C. A1 - Tuchscherer, P. A1 - Voronine, D. V. T1 - Coherent spectroscopies on ultrashort time and length scales JF - EPJ Web of Conferences N2 - Three spectroscopic techniques are presented that provide simultaneous spatial and temporal resolution: modified confocal microscopy with heterodyne detection, space-time-resolved spectroscopy using coherent control concepts, and coherent two-dimensional nano-spectroscopy. Latest experimental results are discussed. KW - coherent spectroscopy KW - ultrashort time KW - length scale Y1 - 2013 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-129073 VL - 41 ER - TY - JOUR A1 - Babski, Julia A1 - Haas, Karina A. A1 - Näther-Schindler, Daniela A1 - Pfeiffer, Friedhelm A1 - Förstner, Konrad U. A1 - Hammelmann, Matthias A1 - Hilker, Rolf A1 - Becker, Anke A1 - Sharma, Cynthia M. A1 - Marchfelder, Anita A1 - Soppa, Jörg T1 - Genome-wide identification of transcriptional start sites in the haloarchaeon Haloferax volcanii based on differential RNA-Seq (dRNA-Seq) JF - BMC Genomics N2 - Background Differential RNA-Seq (dRNA-Seq) is a recently developed method of performing primary transcriptome analyses that allows for the genome-wide mapping of transcriptional start sites (TSSs) and the identification of novel transcripts. Although the transcriptomes of diverse bacterial species have been characterized by dRNA-Seq, the transcriptome analysis of archaeal species is still rather limited. Therefore, we used dRNA-Seq to characterize the primary transcriptome of the model archaeon Haloferax volcanii. Results Three independent cultures of Hfx. volcanii grown under optimal conditions to the mid-exponential growth phase were used to determine the primary transcriptome and map the 5′-ends of the transcripts. In total, 4749 potential TSSs were detected. A position weight matrix (PWM) was derived for the promoter predictions, and the results showed that 64 % of the TSSs were preceded by stringent or relaxed basal promoters. Of the identified TSSs, 1851 belonged to protein-coding genes. Thus, fewer than half (46 %) of the 4040 protein-coding genes were expressed under optimal growth conditions. Seventy-two percent of all protein-coding transcripts were leaderless, which emphasized that this pathway is the major pathway for translation initiation in haloarchaea. A total of 2898 of the TSSs belonged to potential non-coding RNAs, which accounted for an unexpectedly high fraction (61 %) of all transcripts. Most of the non-coding TSSs had not been previously described (2792) and represented novel sequences (59 % of all TSSs). A large fraction of the potential novel non-coding transcripts were cis-antisense RNAs (1244 aTSSs). A strong negative correlation between the levels of antisense transcripts and cognate sense mRNAs was found, which suggested that the negative regulation of gene expression via antisense RNAs may play an important role in haloarchaea. The other types of novel non-coding transcripts corresponded to internal transcripts overlapping with mRNAs (1153 iTSSs) and intergenic small RNA (sRNA) candidates (395 TSSs). Conclusion This study provides a comprehensive map of the primary transcriptome of Hfx. volcanii grown under optimal conditions. Fewer than half of all protein-coding genes have been transcribed under these conditions. Unexpectedly, more than half of the detected TSSs belonged to several classes of non-coding RNAs. Thus, RNA-based regulation appears to play a more important role in haloarchaea than previously anticipated. KW - Archaea KW - dRNA-Seq KW - Promoter KW - Non-coding RNAs KW - sRNA KW - Haloferax volcanii KW - Transcriptome KW - Leaderless transcript KW - Antisense RNA Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-164553 VL - 17 IS - 629 ER -