150 



Studies in Milk Secretion 



Days 



Remarks ... 



Pituitary milk c.c. 



Ratio: morn, yiekl 

 (= 100) to pitui- 

 tary yield 



% fat pituitary milk 



Remarks 



Pituitary c.c. 



Ratio: morn, yield 

 (= 100) to pitui- 

 tary yield 



% fat pituitary milk 



Table III. 

 Exjf). I. Goat II. 



12 3 4 5 



— Phloridzin Phloridzin — — 



40 3.3 29 40 40 



31 21 15 28 57 



9-7 



18 

 35 



11-3 



8-4 



Phloridzin 



5 



54 



9-7 



14-5 



Exp. II. Goat I. 



lG-6 



10 



56 



10-1 



13 

 41 



12-0 



14-5 — 



11 

 26 



11 

 24 



12 

 24 



7-1 



7-0 



From the results shown in the previous tables it would seem that 

 the amount of milk produced by the action of pituitary extract varies 

 with the state of nutrition. However the ratio, morning yield to pitui- 

 tary yield, rises with the fall in nutrition and falls as the nutrition rises 

 again so that the yield obtained as a result of pituitary injections tends 

 to be more constant than the morning or daily yield. Pituitary ex- 

 tract seems to act on some store which is not affected so much by 

 external conditions as is the daily yield. At first sight it would appear 

 possible that this store is situated in the ducts and alveoli of the mam- 

 mary gland ; but if this is so, it is difficult to explain the small effect 

 of pituitary extract on goats in a low state of nutrition, for during these 

 experiments there has been no time for the duct or alveolar, space 

 to change. 



It will be seen that the percentage of fat in the pituitary milk rises 

 with the fall in nutrition as it does in the case of normal milk till, in 

 some cases, milk with practically 30 per cent, fat has been obtained. 



15 

 24 



8-9 9-8 



Adrenalin. 



It will be noticed that Ott and Scott classify adrenalin as an inhi- 

 bitor of milk secretion ; this seems surprising since adrenalin is known 

 to have many of the same actions on the body as pituitary extract has, 

 causing contraction of plain muscle, hyperglycaemia and glycosuria. 



The effect of injections of adrenalin into lactating goats has been 

 tried in order to find out, if possible, its mode of action. 



