vii KATABOLIC CONSTITUENTS OF URINE 405 



immersion in cold water, complained of fatigue and headache, 

 followed by slight albuminuria of short duration. 



Albuminuria can be experimentally produced in animals by 

 abnormal increase of blood pressure in the vascular parts of the 

 kidneys. We shall speak of this in the next chapter, in discussing 

 the secretion of urine. 



In almost all cases of spontaneous or experimental albuminuria, 

 serum-globulin is associated with serum-albumin in the urine, in 

 proportions that vary considerably from 8-60 per cent of the total 

 coagulum (Hammarsten, Hoffmann, Patella, Czatary). Serum- 

 globulin may be present without serum -albumin, or vice versa. 

 In true nephritis (Bright's disease'] the so-called urinary casts are 

 invariably present in urine, showing that the fibrinogen of the 

 blood plasma is also thrown out by the kidneys, and suddenly 

 converted into fibrin, which takes the cylindrical form of the renal 

 canaliculi. The total amount of protein eliminated by the kidneys 

 rarely exceeds 1 per cent, but may, in certain cases, amount to 

 4 per cent (Hoppe-Seyler). 



The cases of Jiaematuria, or admixture of blood in toto with 

 urine, or of the blood pigment only (haemoglobinuria or methaemo- 

 globinuria), belong exclusively to pathology. 



Enzymes may also be included among the proteins of the 

 urine, pepsin (Briicke, 1861) and the diastatic ferment (Cohnheim, 

 1863) being constantly present in normal urine. 



Pepsin is abundant in the urine passed in the morning before 

 a meal (Sahli, Mees), scanty in the urine secreted in the first hours 

 after a meal (Sahli, Gehring, Hoffmann). After prolonged fasting 

 there is no trace of it, but after consumption of food it appears 

 again abundantly (Leo, Senator). In disease it seems to diminish, 

 but observations on this point are at variance, so that the fact 

 cannot be used in diagnosis (Leo, Wasilewski, Mya and Bonfanti, 

 Stadelmann). 



The presence of trypsin in urine is denied by Sahli, regarded 

 by others as inconstant. Bendersky, however, always detected a 

 substance in normal urine which dissolved fibrin in alkaline 

 solution. This fact was confirmed in our laboratory by Tarulli 

 in the urine passed before a meal. The substance disappears 

 during digestion, and subsequently reappears. 



The diastatic enzyme is constant in the urine of man and 

 rabbits. It increases after a meal, and diminishes in the night- 

 urine, and during abstinence (Gehring, Hoffmann). 



Till recently it was assumed that these digestive enzymes 

 were included among the specific products of the gastric, 

 pancreatic, and salivary secretions, which, after fulfilling their 

 . digestive functions in the gastro-intestinal canal, are reabsorbed 

 previous to decomposition, brought into the circulation, and 

 eliminated by the kidneys. At present the tendency is rather to 



