i66 INTERNAL SECRETIONS OF THE OVARY 



animals. They use the 6-8 gms. immature mouse, and give six 

 doses over forty-eight hours. The result appears in about lOO 

 hours. They define the mouse unit of anterior pituitary hormone 

 as the amount which given in six doses will produce precocious 

 oestrus, including the ovarian changes, in the 6-8 gms. mouse 

 within 100 hours. 



(/) PREPARATION AND PROPERTIES 



Zondek and Aschheim have obtained aqueous extracts of the 

 anterior pituitary body which have the same effect as the 

 implants. Further, they have described (658) the preparation 

 from urine as follows: The urine is acidified with acetic acid, 

 filtered, and evaporated down to half the volume. It is then 

 extracted with ether to remove oestrin. The watery residue is 

 dialysed and evaporated to dryness. By further purification 

 (details not given) a whitish amorphous water-soluble powder is 

 obtained. These authors give a table of the comparative 

 chemical properties of oestrin and the anterior pituitary sub- 

 stance (Table 10). 



Table 10. — Comparison of Properties of (Estrin 

 AND THE Anterior Pituitary Substance. 



Smith (577) has reported that anterior pituitary substance is 

 inactive when administered by mouth; probably the active prin- 

 ciple is destroyed by the digestive enzymes. 



{g) DISTRIBUTION OF THE ANTERIOR PITUITARY 



HORMONE 



After the discovery of the characteristic effects of the injection 

 of anterior pituitary preparations, attempts were soon made to 



