THE INHIBITORY ACTION OF VARIOUS STEROIDS ON THE HOOKER-FORBES ASSAY FOR PROGESTERONE¹

Abstract

THE effects that one hormone may have upon the physiological action of another is of considerable interest and importance. Both “synergistic” and “antagonistic” interactions have been observed, and some of these have been discussed recently at some length by Courrier (1951). The possibility that the effect produced by one steroid hormone may be augmented or inhibited by another is of particular significance in procedures for quantitative assays. Hooker and Forbes (1947, 1949) described a microbioassay for progesterone which they considered specific. They found that the accuracy of the assay was unaffected by the presence of estrogen (Hooker and Forbes, 1947). Inasmuch as the response observed by Hooker and Forbes involved changes in the connective tissue of the endometrium of the mouse uterus, this independent action of progesterone seemed to be in conflict with the observations by Morel (1948) on the antagonistic action of estrogen on the decidual reaction in castrated mice.