TY - JOUR A1 - Dörje, F. A1 - Friebe, T. A1 - Tacke, Reinhold A1 - Mutschler, E. A1 - Lambrecht, G. T1 - Novel pharmacological profile of muscarinic receptors mediating contraction of the guinea-pig uterus N2 - The present study was designed to further characterize the muscarinic receptors mediating contraction of the guinea-pig uterus. The affinities of various selective muscarinic antagonists were determined and compared with those obtained at M\(_1\) (rabbit vas deferens), M\(_2\) (guinea-pig atria) and M\(_3\) receptors (guinea-pig ileum). The contractile responses of uterine smooth muscle from immature guinea-pigs to carbachol (pD\(_2\) = 5.73) were competitively antagonized by pirenzepine (pA\(_2\) = 7.04), AF-DX 116 (11-[[2-[(diethylamino)methyl]-1-piperidinyl] acetyl]- 5,11-dihydro-6H -pyrido[2,3-b][1 ,4]benzo. diazepin-6-one) (pA\(_2\) = 6.96), himbacine (pA\(_2\) = 7.92), methoctramine (pA\(_2\) = 7.52), 4-DAMP (4-diphenylacetoxy- N-methylpiperidine methiodide) (pA\(_2\) = 8.87) and sila-hexocyclium (pA\(_2\) = 8.81). A comparison of affinity values indicates that the muscarinic receptors present in guinea-pig uterus display a novel pharmacological profile which is not consistent with the presence of either an M\(_1\), M\(_2\) or M\(_3\) receptor. The affinities determined for the different antagonists rather showed a close similarity to those obtained at muscarinic receptors present in rat striatum and NG108-15 cells which are considered pharmacological equivalents (M\(_4\) receptors) of the m4 gene product. We thus hypothesize that the guinea-pig isolated uterus preparation may serve as a simple functional assay system to study the pharmacology of M\(_4\) receptors. KW - Anorganische Chemie KW - Muscarinic receptors KW - M4 receptors KW - Guinea-pig uterus KW - Pirenzepine KW - Methoctramine KW - Sila-hexocyclium Y1 - 1990 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-64071 ER - TY - JOUR A1 - Gorboulev, Valentin A1 - Akhundova, Aida A1 - Luzius, Heike A1 - Fahrenholz, Falk T1 - Molecular cloning of substance P receptor cDNA from guinea-pig uterus N2 - A cDNA encoding guinea-pig uterine substance P (SP) receptor has been isolated using the homology screening approach. Northern blot analysis reveals that the corresponding mRNA, of approx. 4.8 kb, is expressed in all tissues tested, but predominantly in the uteri of non-pregnant animals; during pregnancy its expression is reduced. The guinea-pig SP receptor was expressed in COS-7 cells and demonstrated relative Iigand affinity in the order: SP >> neurokinin A > neurokinin B. KW - Biologie KW - Substance P receptor KW - G-protein-coupled receptor KW - Guinea-pig uterus KW - COS cell expression Y1 - 1992 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-59293 ER -