EDEMA 



177 



portant, unless there are associated inflammatory changes in the kidneys. 

 In fact, the blood urea is frequently lower than the average normal, and 

 the phenolsulphonephthalein output higher. Volhard has also shown that 

 the ability to concentrate sodium chlorid in the urine is nearly always 

 retained, and that the kidneys are able to excrete large amounts of water 

 within a short time. The latter point has been demonstrated both by 

 rapid administration of large amounts of water and by elevating the 

 edematous extremities. . 



The changes in the blood in this condition may be striking. Accord- 

 ing to Volhard, the blood is highly concentrated in the early stages of 

 the disease, when the edema may be greatest.. The number of red cells 

 is near the maximum of normal figures, and the viscosity may be increased. 

 As soon, however, as the excretion of water becomes improved, especially 

 in the later stages, there is a marked reduction in the protein content of 

 the blood serum. The specific gravity of the serum may fall as low as 

 1.015. Both the albumin content and the specific gravity of the urine 

 may be higher than that of the blood. 



The protein constituents of the blood serum have been analyzed by 

 Epstein, who has found that there is marked diminution of total protein, 

 but that the loss is entirely in the albumin fraction, whereas the globulin 

 is usually increased. The result is a great increase in the proportion of 

 the total protein represented by globulin (Table XII). 



TABLE XII 



AVERAGE COMPOSITION OF BLOOD SEBA 

 (Epstein) 



Epstein also finds the cholesterin content of the blood serum to be 

 markedly increased (Table XIII). This results in a milky or pseudo- 

 chylous appearance of the serum. Eecent analyses of blood serum for 

 cholesterin content by Port (6) and by Stepp(c) are in every way compar- 

 able with those of Epstein. Stepp also publishes analyses of the blood 

 serum of three dogs, after nephrectomy, in which there was marked in- 

 crease of cholesterin. 



The non-protein nitrogen of the blood and the urea nitrogen are often 

 lower than the average normal. In mixed forms of nephritis, or in cases 

 of anuria, the figures may be somewhat higher than normal, but the pure 



