1. Departments of Obstetrics & Gynecology, Urology, and Medicinal Chemistry and Pharmaceutics, University of Oklahoma Health Sciences Center, P.O. Box 26901, Oklahoma City, Oklahoma 73l90, Departments of Chemistry and Biochemistry and Molecular Biology, Oklahoma State University, Stillwater, Oklahoma 74078, The Samuel Roberts Noble Foundation, Inc., 2510 Highway 199 East, Ardmore, Oklahoma 73402, and Kettering-Meyer Laboratories, Southern Research Institute, P.O. Box 55305, Birmingham, Alabama 35255-5305