title: The influence of aromatic substitution on the negative inotropic action of verapamil in the isolated cat papillary muscle.
abstract: The influence of ring substitution on the negative-inotropic action of the Ca-antagonist verapamil (Isoptin) by means of qualitative and quantitative analyses of the structure-activity relationships has been investigated. The relative contribution of the two aromatic rings to the negative-inotropic potency of verapamil was tested. a) Ring substituents strongly influence the negative-inotropic potency (ED50 values from 7.9 x 10(-7) mol/l to 1.3 x 10(-4) mol/l). The character of the negative-inotropic effect typical for verapamil is not altered (except by very bulky substituents).
mesh_terms: D000818:Animals; D002415:Cats; D009200:Myocardial Contraction / Q000187:drug effects*; D010210:Papillary Muscles / Q000187:drug effects; D013329:Structure-Activity Relationship; D014700:Verapamil / Q000031:analogs & derivatives* / Q000494:pharmacology
chemical_list: D014700:Verapamil