3TABVA1 [I 



comparing the creatine and creatinine output with that of aitrogen t" 

 determine whether all of the aitrogen liberated by the breakdown of 

 muscle has been excreted, or whether some has been retained eitl 

 resynthesis in the muscle itself or for use elsewhere, li' the mm 

 breakdown as calculated from the creatine-creatinine outpul 

 than thai calculated from the nitrogen, synthesis of the n< tine 



remainder must be wrringj whereas if the breakdown calculated from 



nitrogen is greater than thai calculated from en 

 sues than muscle musl be contributory. Stored nitrogen or. free nil 

 gen in transit from tissue to tissue for utilization is the most likely 

 source of such excess oil rogen. 



That transference of nitrogenous substances from place to place in the 

 body in starvation is proved 1 I by the constanl presen >f amino ni- 

 trogen in the blood and tissues Van Slyke ; and '-! by th< 

 copious water drinking. The Latter causes a decided increase in t ; 

 put of nitrogen, bu1 it does not appear that the extra nitrogen is d 

 increased protein breakdown. It is probable, however, thai in such <•■ 

 there would also be an increase in endogenous protein metabolism, 

 the washed-ou1 fvc nitrogen would have to be replaced. 



Excretion of Purines. Although at firsl they fall sum. -what, the total 

 amount increases as the fasl progresses. Perhaps the firsl decli 

 due to genera] using up of hypoxanthine of muscle and the lat< 

 to the breakdown of nuclei (page 638 . 



Excretion of Sulphur. It is importanl to compare tl 

 sulphur and nitrogen. In the early days of starvation a ratio of 17 N: 1 S 

 has been found, bul later one of 14.5: 1, which is practically the same 



as that in mnsele i i. e.. 11:1. indicating that late in fasting the main 



source of protein supply is muscle. 



Several of the changes observed during starvation can be attribul 

 to the condition of acidosis which Bupervei ids are derived 



from incomplete combustion of fal Bee page 68 nd are repn 



by |9-oxybutyric, the amount being sometimes considerable 10-15 grams 

 a daj . 'specially in obese individuals. The large ammonia tion 



(sometimes 2 grams a day' is evidently for the purp< utraliri 



the excess of acid. Another consequence of the acidosis is tl sline 



in the alveolar tension of « page 354 . and it - hie that si 



the circulatory changes shown in the chart may also be dependenl on 

 it. The method of repeated fasting us.d for reducing obesity is q 

 safe if the acidosis is carefullj watched. 



.Man;, secondary changes also occur in the starving organism. Thus. 

 the mobilization of fal is often responsible for a pronounced ii ■• in 



the fat content of the blood see p '- and tl 



