Metabolism of (4-14C) LYNESTRENOL IN Thai women

The metabolism of 4-14-carbon lynestrenol was studied in Thai women, and the results were compared with a similar study of European women. The half-lives of radioactivity in plasma and urine, and the levels of urinary radioactivity found in free, sulphate, and acid-hydrolyzed fractions were similar to those reported in the European study. The levels of radioactivity observed in enzyme-hydrolyzed urinary extracts were significantly lower among Thai women (p=.01), though the difference was probably due to the use of a different enzyme prepararation. The chromatographic mobilities of free and enzyme-hydrolyzed urinary extracts were similar for both groups, though the levels for the sulphate fractions were so variable in the Thai group that they defied comparison. The results indicate that the metabolism of lynestrenol in European and Thai women is similar, and that the observed differences are unlikely to have biological significance.