SPECIFICITY OF THE INTRAUTERINE TEST FOR PROGESTERONE1

Abstract

In an earlier paper (Hooker and Forbes, 1947) a bioassay that detects 0.0002 μg of progesterone was described. The sensitivity of the test readily permits the measurement of levels of this hormone in blood (Hooker and Forbes, 1947, 1949) and other body fluids, and offers promise of being useful in investigating several aspects of the metabolism of progesterone. To be of more than seriously limited value, however, an assay must be more or less specific, irrespective of its sensitivity. It has already been reported (Hooker and Forbes, 1947) that estrone, α-estradiol, desoxycorticosterone acetate, and testosterone failed to elicit the reaction used as a test for progesterone. The specificity of the test has been examined further by administering several additional substances. All of the substances tested are listed in Table 1. Included are (1) compounds reported to duplicate the action of progesterone in other tests, (2) compounds considered to be metabolites or possible precursors of progesterone,