THE BIOASSAY OF PROGESTERONE

IT WAS first observed by Lutwak-Mann (1) that gonadotrophins, progesterone and certain other luteoids injected into estrous adult or estrogen-primed immature rabbits produced marked increases in the content of uterine carbonic anhydrase, the extent of which depended upon the dosage, and this was accompanied by histological evidence of progestational proliferation (2). It was therefore suggested that the measurement of endometrial carbonic anhydrase might be used as a basis for progestin assay, and subsequently Lutwak-Mann and Adams (3) have compared endometrial carbonic anhydrase titers and the degree of progestational proliferation as measured by the Robson (4) scale, using progesterone and other steroids. The specificity of the enzyme reaction appears to be substantiated by their data, but quantitation and definition of sensitivity were not attempted. In this paper we present: (a) a statistical analysis of the dosage response data for progesterone in the conventional Clauberg rabbit, (b) a comparison of...