Lipoid Material in Renal Epithelium. 223 



and without any fixation were frozen, sections made, and stained 

 for lipoid material by Herxheimer's Scharlach R. method. Such 

 sections were counterstained with Mayer's Haemalum. Other 

 tissue from both kidneys was fixed with formaline, Zenker's fluid, 

 and in corrosive-acetic, imbedded in either paraffin or celloidin, and 

 used for a general histological study. 



Normal Control Animals. 



During the eight days of observation, urine formation by the 

 seven normal control animals has varied from a minimum output 

 of 385 c.c. to a maximum output of 621 c.c. The urine was free 

 from both albumin and glucose. The elimination of phenolsul- 

 phonephthalein by the respective animals in a two-hour period 

 varied from 65 per cent, to 80 per cent. The blood urea varied 

 from 12 to 18 mgs. per 100 c.c. of blood. The reserve alkali of 

 the blood was normal and gave readings between 8.0 to 8.1. 



When such animals were killed without the use of an anesthetic 

 and kidney tissue studied for the amount and distribution of 

 stainable lipoid material by the use of Scharlach R., the following 

 observations were made. The endothelium of the glomerular 

 capillaries and other vascular tissue of the kidney failed to show 

 the presence of stainable lipoid. The convoluted tubule epi- 

 thelium in young animals such as have been used in this study 

 does not show the presence of stainable lipoid with Scharlach R. 

 In old normal animals as has been previously noted, 1 stainable 

 lipoid may appear in the epithelium of this portion of the tubule 

 in the form of fine dust-like particles. All of the normal control 

 animals show stainable lipoid in both the descending and ascending 

 limbs of Henle's loops. In this portion of the tubule such material 

 appears as small particles or fused droplets. 



The study of the normal control group of animals indicates 

 that stainable lipoid as demonstrated by Scharlach R. with Herx- 

 heimer's technique of staining is confined to the epithelial cells 

 of the loops of Henle. Lipoid material in this location has no 

 harmful effect on the functional capacity of the kidney and does 

 not interfere with that function of the kidney which is concerned 

 with maintaining a normal acid-base equilibrium of the blood. 



1 MacNider, Wm. deB., Jour. Pharm. and Exp. Therap., 1921, xvii, 289. 



