THE PITUITARY BODY 



It is probable that the successful initiation of lactation by- 

 means of the crude anterior pituitary extracts depends upon 

 the presence of adrenal cortical stimulating hormone (as well 

 as, perhaps, that affecting carbohydrate metabolism) in such 

 extracts.'^ According to Gaunt and Tobin (1936), the adrenal 

 glands contain no substance with lactogenic effects. How- 

 ever, after bilateral adrenalectomy has been performed in 

 lactating rats, the secretion of milk ceases but can be re- 

 stored by the administration of about twice the dose of 

 adrenal cortical extract necessary to prevent death. Smaller 

 doses can be used in conjunction with salt therapy, and 

 sometimes salt therapy alone is sufficient. After hypophysec- 

 tomy in lactating guinea pigs, lactation ceases but can be 

 initiated again by the administration of refined lactogenic 

 extract and adrenal cortical hormone (Gomez and Turner, 

 1936; Nelson and Gaunt, 1936.)''^ However, this treatment 

 permits lactation for only a few days and does not prevent 

 the involution of the breasts. Either extract by itself is of no 

 value. Gomez and Turner (1937) later reported on the use 

 of adrenal cortical stimulating hormone, obtained from the 

 anterior pituitary, in place of adrenal cortical extract. By 

 injecting an extract containing this hormone as well as lac- 

 togenic extract and glucose, they could maintain lactation 

 in hypophysectomized guinea pigs for as long as 8-15 days. 



The effects of ''sex hormones'' on lactation, i. Oestrogens. — 

 Numerous earlier reports indicated that the secretion of 

 lactogenic hormone as indicated by lactation is inhibited by 

 the internal secretions of the gonads. For example, ovariec- 

 tomy may be followed promptly by lactation. On the other 



'^Thyrotropic hormone may be of importance but certainly is not essential, 

 inasmuch as lactation takes place in thyroidectomized mammals (see pp. 165-66). 



Schooley, Riddle, and Bates (1937) found that the response of the crop-glands 

 of one pigeon following the injection of lactogenic hormone was not prevented by 

 adrenalectomy four days before. 



'•5 Gomez and Turner (1936-37) beheved that it is important also to administer 

 glucose, which they injected in amounts as high as 100 mg. per ico gm. of body- 

 weight daily. 



f 160 1 



