Lipoid Material in Renal Epithelium. 227 



these cells that have been preceded by the appearance of stainable 

 lipoid have become more marked. The cells show an advanced 

 swelling, which frequently obliterates the lumen of the tubules. 

 Vacuolation and necrosis are well advanced in many of the cells, 

 especially in those of the convoluted tubules. The glomerular 

 vessels are engorged with blood. Occasionally a slight exudate is 

 seen in the subcapsular space. The endothelium of the capillaries 

 has failed to show stainable lipoid. 



Conclusions. 



1. Lipoid material stainable with Scharlach R. is constantly 

 found in the cells of the loops of Henle in normal dogs. The 

 presence of such material in this location is not indicative of a 

 pathological kidney. The functional capacity of such a kidney 

 is normal. 



2. When animals are given one subcutaneous injection of 6 

 mg. of uranium nitrate per kilogram, the earliest evidence of 

 injury to the kidney consists of an increase in the amount of stain- 

 able lipoid in the cells of the loops of Henle. At this stage of the 

 intoxication there is no evidence of a functional disturbance on 

 the part of the kidney and no change takes place in the acid-base 

 equilibrium of the blood. 



3. At a later stage of such an intoxication (12 hours) stainable 

 lipoid material appears in the convoluted tubule epithelium. The 

 vascular tissue of the kidney is uninjured. Associated with such 

 a disturbance in the metabolism of these cells that leads to the 

 appearance of stainable lipoid in the cell there occurs a reduction 

 in the elimination of phenolsulphonephthalein, a depletion in the 

 alkali reserve of the blood and the appearance of albumin and 

 glucose, or glucose alone in the urine. 



4. Following this initial injury to the tubular epithelium 

 changes of a more distinctly degenerative type appear in these 

 cells and the functional capacity of the kidney is more severely 

 impaired. 



