A biochemical investigation of the corpus luteum

A method for the preparation of potent extracts of the corpus luteum, which produce progestational proliferation and inhibition of the reaction of the uterus to pituitrin on subcutaneous injection in the rabbit,is described. Both the oxytocic and pressor fractions of the posterior lobe are inhibited.Small doses of alpha in oily solution do not interfere with the progestational or inhibitory reactions of the corpus luteum extracts; large doses of alpha (more than 3000 mouse units) prevent the progestational reaction, but the pituitrin reaction is still inhibited.The crude extract was partitioned between volatile media, and fractions obtained, which produced either one effect or the other. It is suggested that the proliferative and inhibitory reactions may be due to two different factors in the corpus luteum. The names beta and gamma are suggested for the two factors.Prolonged treatment of the crude extract with acetone or methyl alcohol destroys gamma without affecting beta.Saponification destroyed both the proliferative and inhibitory actions of the corpus luteum preparations.Inhibition without proliferation was obtained with extracts of human placenta.Proliferation without inhibition was obtained with extracts of suprarenals; thus the statement of Englehart was confirmed