1. Institut für Experimentelle Endokrinologie (S.P., C.S.H., J.K.), Charité-Universitätsmedizin Berlin, Charité Campus Virchow Klinikum (Südring 10), 13353 Berlin, Germany
2. Department of Physiology and Pharmacology (T.S.S.), Oregon Health & Science University, Portland, Oregon 97239-3098