1. Departments of Medicinal Chemistry and DMPK, Cardiovascular and Urogenital Centre of Excellence for Drug Discovery, GlaxoSmithKline Research and Development, Medicines Research Centre, Gunnels Wood Road, Stevenage, Herts SG1 2NY, U.K., and Department of Assay Development and Compound Profiling, Harlow Research 2, GlaxoSmithKline, New Frontiers, Science Park, Third Avenue, Harlow, Essex CM19 5AD, U.K.