148 Studies hi Milk Secretion 



has been made to confirm the conclusions reached by Ott and Scott 

 with regard to the other glands. 



Pituitary Extract. 



Effect of nutrition on the flow of milk following an injection. 



In a former paper by one of us^ the action of pituitary extract on 

 the mammary gland was investigated and it was noticed that the effect 

 of pituitary extract varied with the state of nutrition of the animal. 

 Ott and Scott^ noticed that when a feverish condition arose in a goat 

 injections of pituitary extract acted very feebly. The eiSect of pituitary 

 extract was therefore studied in animals under conditions of reduced 

 nutrition, as described in the previous paper^, in the hope that this 

 would throw light on the mode of action of the extract. 



Pituitary extract*, in each case 1 c.c, was injected daily into goats 

 during a period of sudden change from a high to low condition of nutri- 

 tion. This change was brought about as described in the previous 

 paper^ and three series of experiments have been performed : (a) with- 

 out food for a few days and then return to abundant nourishment; 

 (b) without food for a few days together with an injection of phloridzin 

 followed by an abundant supply of food; (c) injections of phloridzin 

 under normal conditions of feeding. 



The goats were milked dry each morning and immediately after 

 1 c.c. of pituitary extract w.as injected. It has previously been shown 

 that under normal conditions injections at intervals of one day give 

 no immunizing effect, injections of 1 c.c. at such intervals giving 

 approximately the same amount of milk. Since it has been previously 

 shown that the action of the extract was complete under half an hour 

 after an injection, the goats were milked after this period, and the 

 amount obtained is taken as the yield resulting from pituitary injection. 

 The percentage of fat in each sample was determined by Gerber's 

 method. 



The following tables Nos. I, II and III give the results obtained in 

 the various experiments of the series (a), (b) and (c) respectively: 



1 Jour. Exp. Physiol. Vol. vi, 1913. 

 ^ TheraiKutic Gazette, October, 1911. 



* "Studies in Milk Secretion," Part I. Tiiis Journal. 



* Messrs Burroughs and Wellcome's extract of the posterior lobe was used in all these 

 experiments. 



