632 



LECTURE XXVII. 



the albumin in the organism is protected to a certain extent from con- 

 sumption. On the very first day of fasting, there is in the majority of 

 cases a noticeably high elimination of nitrogen, and especially when the 

 food has been rich in proteins. The rise in the amount of nitrogen elimi- 

 nated, which in individual cases, as with rabbits, for example, reaches a 

 maximum on the third to the fifth day from the beginning of the fasting, 

 is taken as a guide for determining the time when the carbohydrate stores 

 have been exhausted; i.e., when the albumin-sparing factor has been 

 eliminated. 1 Moreover, this increase in the decomposition of albumin is 

 not a constant phenomenon, and evidently depends upon the species. In 

 the case of rabbits, especially, it is hard to determine the exact day when 

 the starvation period begins. These animals have an extremely volumi- 

 nous intestine, and particularly in the caecum there is always a mass of only 

 partly utilized material upon which the animal may subsist for some time. 

 In the case of dogs, in general there is a uniform, slowly diminishing elimi- 

 nation of nitrogen. 2 Voit has shown the influence of a preliminary diet, 

 rich in protein, upon the elimination of nitrogen during the first day of 

 fasting, by the following three experiments. 3 He determined the amount 

 of nitrogen eliminated daily. Before beginning the experiment the first 

 dog was fed daily with 2500 grams of meat, the second dog received 1500 

 grams of meat, while the third dog was fed with a mixed diet, poor in 

 proteins. 



Nitrogen Eliminated in Grams per 24 Hours. 



A summary of the nitrogen elimination in a five-day fasting experiment 

 with men, is given by the following values published by Tigerstedt : 4 



1 R. May: Z. Biol. 30, 1 (1894). 



2 M. Kumagawa and R. Miura: Arch. Anat. Physiol. 1898, 431. 



3 Voit: Hermann's Handbuch, 6, 1, p. 89 (1881). 



4 Robert Tigerstedt: Lehrbuch der Physiologic des Menschen. 3 Aufl. Bd. 1, p. Ill 

 (Leipsic, 1905). 



