1. From the Department of Pharmacology, College of Medicine, Howard University, Washington, DC (B.O.O., C.M.F.)
2. Department of Pharmacology and Experimental Therapeutics, Louisiana State University Health Sciences Center, New Orleans (E.L.)
3. Southeast Louisiana Veterans Health Care Systems, New Orleans (E.L.)
4. Cardiovascular Center of Excellence, Louisiana State University Health Sciences Center, New Orleans (E.L.).