Pharmacological Investigation of Drug Receptor Interactions

• Pharmacological studies on isolated organs
• Cloning and expression of receptors
• Radioligand binding studies
• Functional cellular assays (cAMP, calcium mobilisation)
• New methods: fluorimetric methods as an alternative to radioligand binding to study G-Protein-coupled receptors

Selected publications and abstracts:

• P. Igel, D. Schnell, G. Bernhardt, R. Seifert, A. Buschauer, Tritium-labeled N1-[3-(1H-imidazol-4-yl)propyl]-N2-propionylguanidine ([3H]UR-PI294), a novel high affinity histamine H3 and H4 receptor radioligand. ChemMedChem 4 (2), 225-231 (2009).
• M. Keller, N. Pop, C. Hutzler, A. G. Beck-Sickinger, G. Bernhardt, A. Buschauer, Guanidine - acylguanidine bioisosteric approach in the design of radioligands: Synthesis of a tritium-labeled N(G)-propionylargininamide ([3H]-UR-MK114) as a highly potent and selective neuropeptide Y Y1 receptor antagonist. J. Med. Chem. 51 (24), 8168-8172 (2008).
• R. Ziemek, E. Schneider, A. Kraus, C. Cabrele, A.G. Beck-Sickinger, G. Bernhardt, A. Buschauer, Determination of affinity and activity of ligands at the human neuropeptide Y Y4 receptor by flow cytometry and aequorin luminescence. J. Recept. Signal Transduct. 27 (4), 217-233 (2007).
• H. Preuss, P. Ghorai, A. Kraus, S. Dove, A. Buschauer, R. Seifert, Mutations of Cys-17 and Ala-271 in the human histamine H2 receptor determine the species-selectivity of guanidine-type agonists and increase constitutive activity. J. Pharmacol. Exp. Ther. 321 (3), 975-982 (2007).
• H. Preuss, P. Ghorai, A. Kraus, S. Dove, A. Buschauer, R. Seifert, Constitutive activity and ligand selectivity of human, guinea pig, rat, and canine histamine H2 receptors. J. Pharmacol. Exp. Ther. 321 (3), 983-995 (2007).
• S.-X. Xie, F. Schalkhausser, Q.-Z. Ye, R. Seifert, A. Buschauer, Effects of impromidine- and arpromidine-derived guanidines on recombinant human and guinea pig histamine H(1)and H(2)receptors. Arch. Pharm. (Weinheim) 340 (1), 9-16 (2007).
• R. Ziemek, A. Brennauer, E. Schneider, C. Cabrele, A.G. Beck-Sickinger, G. Bernhardt, A. Buschauer, Fluorescence- and luminescence-based methods for the determination of affinity and activity of neuropeptide Y(2) receptor ligands. Eur. J. Pharmacol. 551 (1-3), 10-18 (2006).
• E. Schneider, M. Mayer, R. Ziemek, L. Li, C. Hutzler, G. Bernhardt, A. Buschauer, A Simple and Powerful Flow Cytometric Method for the Simultaneous Determination of Multiple Parameters at G-Protein-coupled Receptor Subtypes. ChemBioChem 7 (9), 1400-1409 (2006).
• S.-X. Xie, G. Petrache, E. Schneider, Q.-Z. Ye, G. Bernhardt, R. Seifert, A. Buschauer, Synthesis and pharmacological characterization of novel fluorescent histamine H2-receptor ligands derived from aminopotentidine. Bioorg. Med. Chem. Lett. 16 (15), 3886-3890 (2006).
• S.-X. Xie, A. Kraus, P. Ghorai, Q.-Z.Ye, S. Elz, A. Buschauer, R. Seifert, N1-(3-Cyclohexylbutanoyl)-N2-[3-(1H-imidazol-4-yl)propyl]guanidine, a potent partial agonist for the human histamine H1- and H2-receptor. J Pharmacol Exp Ther. 317 (3), 1262-1268 (2006).
• S.-X. Xie, P. Ghorai, Q.-Z.Ye, A. Buschauer, R. Seifert, Probing Ligand-Specific Histamine H1- and H2-Receptor Conformations with NG-Acylated Imidazolylpropylguanidines. J. Pharmacol. Exp. Ther. 317 (1), 139-146 (2006).
• L. Li, J. Kracht, S. Peng, G. Bernhardt , A. Buschauer, Synthesis and pharmacological activity of fluorescent histamine H1 receptor antagonists related to mepyramine, Bioorg. Med. Chem. Lett. 13, 1245 - 1248 (2003).
• L. Li, J. Kracht, S. Peng, G. Bernhardt, S. Elz, A. Buschauer, Synthesis and pharmacological activity of fluorescent histamine H2 receptor antagonists related to potentidine, Bioorg. Med. Chem. Lett. 13, 1717-1720 (2003).
• R. Seifert, K. Wenzel-Seifert, T. Bürckstümmer, H. H. Pertz, W. Schunack, S. Dove, A. Buschauer, S. Elz, Multiple differences in agonist and antagonist pharmacology between human and guinea pig histamine H1-receptor, J. Pharmacol. Exp. Ther. 305, 1104 - 1115 (2003).
• C. Moser, G. Bernhardt, J. Michel, H. Schwarz, A. Buschauer, Cloning and functional expression of the hNPY Y₅ receptor in human endometrial cancer (HEC-1B) cells. Can J. Physiol. Pharmacol. 78, 134-142 (2000).
• S. Dove, M. C. Michel, S. Knieps, A. Buschauer, Pharmacology and quantitative structure-activity relationships of imidazolylpropylguanidines with mepyramine-like substructures as non-peptide neuropeptide Y Y₁ receptor antagonists. Can. J. Physiol. Pharmacol. 78, 108-115 (2000).
• J. Kracht, A. Meister, G. Bernhardt, A. Buschauer, Ca²⁺ Mobilisation in Human U-373 MG Glioma Cells as an Assay for Histamine H₁ Receptor Antagonists. Pharm. Pharm. Med. Chem. 333, 48 (2000).
• M. Mayer, L. Li, J. Kracht, G. Bernhardt, A. Buschauer. Determination of Receptor (GPCR) Binding Constants by Flow Cytometry under Equilibrium Conditions. Arch. Pharm. Pharm. Med. Chem. 333, 51 (2000)
• A. Meister, G. Bernhardt, V. Christoffel, A. Buschauer, Antispasmodic Activity of Thymus vulgaris Extract on the Isolated Guinea-Pig Trachea: Discrimination Between Drug and Ethanol Effects. Planta Med. 65, 512-516 (1999).
• C. Moser, G. Bernhardt, A. Buschauer, Efficient Transfection of Human Endometrial Cancer (HEC-1B) Cells with FuGENETM 6 Transfection Reagent. Biochemica, No. 1/1999, 26-27 (1999).
• A. Meister, G. Bernhardt, A. Buschauer, Pharmacology of cotransmission in the electrically stimulated isolated rat ductus deferens nerve-muscle preparation. Naunyn-Schmiedeberg’s Arch. Pharmacol. 358 (Suppl. 1), R241 (1998).