A biological test for corpus luteum extracts in vitro

The present authors have been engaged for some time in the study of the physiological action of various glandular extracts, and more particularly of their influence on the genito-urinary organs. In the course of these investigations, they have discovered a reaction produced by corpora lutea which it is deemed desirable to report in this place. It was found that aqueous or saline extracts of fresh and dessicated corpora lutea of various animals exert a powerfully stimulating action on the vas deferens and seminal vesicles. Small quantities of such extracts when introduced into a chamber containing a freshly excised vas deferens preparation, suspended in warm oxygenated Locke or Tyrode solutions, stimulate the contractions of that organ, and the strength of the contractions is proportional to the strength of the drug introduced. All other glandular extracts tested, with the exception of the suprarenal and orchitic extracts, fail to elicit such contractions of the vas unless administered in very much larger doses. Epinephrin, the active principle of the suprarenal gland, stimulates these contractions more powerfully, while extracts of dessicated orchitic substance also stimulate these contractions only after doses twice as great as those of corpus luteum extracts.

The authors have studied extracts of fresh corpora lutea of the sow, and also extracts of various commercial preparations of the desiccated corpus luteum substance in respect to their action on the vasa deferentia of the dog, cat, rabbit, guinea pig, and the rat, and have found the most suitable and most sensitive preparation for testing the corporus luteum extracts to be a freshly excised vas deferens of the rat in Tyrode's solution. Such preparations, when treated with some corpus luteum extracts, may react by contractions in solutions corresponding to concentrations of 1:2,500 of the fresh gland, and they almost always react to concentrations of 1:1,000 of the fresh gland.