Fluorine-19 NMR studies of tumor-bearing rats treated with difluoromethylornithine

Abstract

Copenhagen rats with implanted metastatic prostate carcinomas have been treated with the drug α‐difluoromethylornithine (DFMO), an inhibitor of the enzyme ornithine decarboxylase. In vivo and in vitro ¹⁹F NMR observations were then carried out on a variety of organs and tissues. The distribution of the drug strongly favored tumor over surrounding muscle. DFMO, which gives a spectrum similar to that of the pH indicator difluoromethylalanine, has potential for determination of in vivo pH. However, in contrast to the alanine analog, DFMO exhibits a considerably smaller shift dependence in response to pH changes. © 1987 Academic Press, Inc.