Corpus Luteum Extracts in Vitro. 



87 



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 excep- 

 tion 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 con- 

 centrations of 1:1,000 of the fresh gland. It was interesting to 

 note that the vas deferens, though very sensitive to the effects of 

 the corpus luteum, does not react to extracts of ovarian substance 

 proper. As far as the authors have been able to gather other 

 data, both experimental and clinical, it seems that the activity 

 of corpus luteum extracts, as indicated by the vas deferens prepar- 

 ations, runs parallel to the activity of those preparations as indi- 

 cated by the other data. This organ, therefore, seems to furnish 

 a convenient method of comparing the physiological activity of 

 various corpus luteum preparations and some criterion for the 

 testing of various chemical principles derived therefrom. Com- 

 plete data of the present investigation will appear in due time in 

 the Journal of Urology. 



