THE PITUITARY BODY 



served a definite but much less marked inhibition, if the 

 ovaries were removed immediately following parturition in 

 rats. Nelson (1937) observed lactation in guinea pigs (nor- 

 mal or gonadectomized of both sexes), when the injection of 

 oestrone, which had caused a complete development of the 

 breasts, was stopped. Also he reported that lactation after 

 oestrone continued in hypophysectomized guinea pigs, if 

 crude pituitary extract was injected; if injections of oestrone 

 were again administered, the lactogenic action of the crude 

 pituitary extract was inhibited. According to Richter (1936), 

 spaying is not followed by any improvement in the quantity 

 or fat-content of the milk in lactating cows; also the duration 

 of lactation is not affected. However, the injection of an 

 oestrogen like oestradiol benzoate is followed by a reduction 

 in the quantity of milk produced by cows (Folley, 1936; 

 Waterman, Freud, and Vos-De Jongh, 1936). Folley studied 

 the effects of oestrogen on some of the constituents of milk 

 and serum. The percentage of fat and non-fatty solids of 

 milk was increased, whereas the nitrogen-partition was not 

 affected, indicating that the milk was not colostrum-like. 

 In the serum the treatment appeared to cause some increase 

 in the concentration of inorganic P and, transiently, of phos- 

 phatase; also there was observed a temporary fall in the con- 

 centration of Ca. 



Other investigators have studied the practical importance 

 of oestrogens as means of suppressing lactation after abortion 

 or stillbirth (Snoeck, 1935; Hoffmann, Mayor, van Tongeren, 

 1936; Mugnai, 1937). Such treatment is of value only when 

 enormous doses are injected. Snoeck injected 100,000 inter- 

 national units of oestrone (?) within three days. Mayor as 

 well as Mugnai concluded that the injection of 250,000 units 

 (mouse-units [Mayor], international units [Mugnai]) of oest- 

 radiol benzoate can completely suppress lactation follow- 

 ing delivery. Breast tension may be lessened by smaller 

 doses. Mugnai recommended the use of oestrogen to inhibit 



[162] 



