456 Urinary Disturbances. 



source (metallic salts, ethereal oils, etc.), and especially the tox- 

 ines of infectious diseases and the products of intracorporeal 

 tissue disintegration and metabolism, may give rise to lesions of 

 the renal epithelial cells and their basement membranes, making 

 it possible for the albumen of the blood to pass through them. 

 In most cases an inflammation of the organ is also present, this 

 factor introducing additional features of increased permeability 

 of the blood vessels, exudation, desquamation of the epithelium 

 and the formation of albuminous casts, blood casts, etc. Some 

 authors look upon evers^ albuminuria as the result of an exuda- 

 tive nephritis of some degree of severity, now unimportant, now 

 serious. 



(For fuller details v. Friedberger-Frohner, Lehrbnch d. klin. Unter- 

 suchungsmcthodcn. Verlag von F. Enke, Stuttgart, III. Aufl.) 



Another important symptom, often met in man. but uncom- 

 mon in animals, is the excretion of sugar in the urine. Although 

 the blood contains a considerable amount of sugar (as much as 

 0.2 per cent."), only minute traces pass into the urine normally. 

 In conditions in which unusual amounts of sugar are brought 

 into the blood {alimentary hyperglyccemia) , and the liver and 

 muscles are no longer able to use it up, the kidneys excrete the 

 excess (glycosuria) ; milk sugar passes most readily and in order 

 thereafter levulose. cane sugar and grape sugar (Krehl). It was 

 discovered by Mering that the administration of the glucoside 

 phloridzin. which contains about forty per cent, of sugar, is fol- 

 lowed by a glycosuria in which not onh' does a considerable 

 amount of the unchanged glucoside pass ofif in the urine, but also 

 sugar from the blood (dextrose) and from the liver (glycogen), 

 probably because of some secondary toxic lesion of the renal 

 epithelial cells. 



A transitory glycosuria, ending in the course of few hours, 

 occurs after puncture of Claude Bernard's glycosuric point, a 

 procedure consisting in making a fine puncture in a certain spot 

 in the floor of the fourth ventricle of the brain. A similar glyco- 

 suria may also be observed after lesions in other parts of the 

 central- nervous system and in a number of intoxications and in- 

 fectious diseases (as in morphine poisoning, curare poisoning and 

 rabies). If the splanchnic be cut at the same time, or the liver 

 be extirpated, or if fasting animals are employed, the glycosuric 

 puncture does not succeed or is uncertain, and therefore the 



