1. Departments of Radiology, and Medical Pharmacology and Physiology, University of MissouriColumbia, Columbia, Missouri 65212 and Research Service, Harry S. Truman Veterans Administration Medical Center, Columbia, Missouri 65201, Medicinal Chemistry Section, National Institute on Drug Abuse, Intramural Research Program, Baltimore, Maryland 21224, Department of Biochemistry and Molecular Biology, University of North Dakota, Grand Forks, North Dakota 58203, and Department of Chemistry, Emory University,...