title: Therapeutic potential of CNS-active M2 antagonists: novel structures and pharmacology.
abstract: Clinical trials with muscarinic agonists or acetylcholine esterase inhibitors for the treatment of Alzheimer's dementia have shown disappointing or equivocal results. An alternative treatment of this disease is the development of drugs which enhance the release of acetylcholine. It is believed, that of the five muscarinic receptor subtypes so far identified in the brain, M2 receptors are located presynaptically in the cortex and hippocampus and upon stimulation inhibit the release of acetylcholine. Based on this hypothesis, we initiated a drug discovery program with the aim of identifying selective and centrally active M2 antagonists which are capable of enhancing cholinergic transmission. These efforts resulted in the successful design and synthesis of novel muscarinic antagonists able to cross the blood brain barrier. Moreover, these compounds show few peripheral effects and possess a superior M2 versus M1 selectivity. The prototype of this novel class of M2 selective compounds, BIBN 99, could be a valuable tool to test the hypothesis that lipophilic M2 antagonists show beneficial effects in the treatment of cognitive disorders.
authors.affiliation: Dr Karl Thomae GmbH, Biberach/Riss, Germany.
authors.forename: H N
authors.initials: HN
authors.lastname: Doods
authors.forename: R
authors.initials: R
authors.lastname: Quirion
authors.forename: G
authors.initials: G
authors.lastname: Mihm
authors.forename: W
authors.initials: W
authors.lastname: Engel
authors.forename: K
authors.initials: K
authors.lastname: Rudolf
authors.forename: M
authors.initials: M
authors.lastname: Entzeroth
authors.forename: G B
authors.initials: GB
authors.lastname: Schiavi
authors.forename: H
authors.initials: H
authors.lastname: Ladinsky
authors.forename: W D
authors.initials: WD
authors.lastname: Bechtel
authors.forename: H A
authors.initials: HA
authors.lastname: Ensinger
mesh_terms: D000818:Animals; D001570:Benzodiazepinones / Q000494:pharmacology; D001921:Brain / Q000187:drug effects / Q000378:metabolism*; D016466:CHO Cells; D003072:Cognition Disorders / Q000188:drug therapy; D006224:Cricetinae; D003984:Dibenzazepines / Q000494:pharmacology* / Q000627:therapeutic use; D015195:Drug Design; D009043:Motor Activity / Q000187:drug effects; D010276:Parasympatholytics / Q000494:pharmacology; D010880:Piperidines / Q000494:pharmacology; D010890:Pirenzepine / Q000031:analogs & derivatives / Q000494:pharmacology; D011725:Pyridines / Q000494:pharmacology* / Q000627:therapeutic use; D051381:Rats; D011976:Receptors, Muscarinic / Q000187:drug effects* / Q000378:metabolism; D013329:Structure-Activity Relationship
chemical_list: D001570:Benzodiazepinones; D003984:Dibenzazepines; D010276:Parasympatholytics; D010880:Piperidines; D011725:Pyridines; D011976:Receptors, Muscarinic; C069054:AQ-RA 741; C079888:BIBN 99; C079889:BIBN 140; D010890:Pirenzepine; C048593:otenzepad