258 



A. BERGSTRAND AND H. BUCHT 



Fig. 3. Large vesicle in glomerular endothelial cell located 

 close to the cell nucleus. Magnification ■ 20,000. 



are very distinct and the vesicle closely resembles 

 a "spherical body". In both pictures "spherical 

 bodies" are observed in the lumen. 



In a previous paper (1) a large polypous protru- 

 sion from the surface of the endothelium in the 

 efferent artery of a rat was described. There were no 

 cell organelles inside it but the wall consisted of 

 three distinct membranes. We believe this is a 

 "spherical body" protruding from the endothelial 

 cell. When the cell membrane bursts, the "spherical 

 body'" with its single membrane (the inner of the 

 two membranes, bordering it in the cell) is ejected. 



The epithelial cells: The nuclei of the epithelial 

 cells were well preserved. There was no increase 

 in the number or size of the epithelial cells and there 

 were no adhesions between the epithelial cells of the 

 capillary walls and those of Bowman's capsule as 

 commonly seen in chronic glomerulonephritis. In 

 the cytoplasm of the epithelial cells changes were 

 observed, which may be regarded as degenerative. 



A large number of vacuoles could be seen in 

 most cells. Many cells were entirely vacuolised, in 

 others only a few, irregular, were visible (Fig. 4). 

 This can imply an increased uptake of fluid from the 

 glomerular filtrate. 



The mitochondria were markedly enlarged. The 

 inner structure was irregular or completely destroyed 



Fig. 4. Left. Mitochondrion in epithelial cell of a glomerulus 

 with irregular abnormal inner structure. Magnification 

 X 50,000. Right. Part of epithelial cell of a glomerulus with a 

 large vacuole. Magnification 12,000. 



as described by Rhodin (5) in the tubular cells during 

 resorption of proteins. It is probable that the glomer- 

 ular filtrate in this patient contains an increased 

 amount of protein, since there is proteinuria. Thus 

 a resorption of protein from this fluid to the capillary 

 epithelial cells may take place. 



The capillary basement membrane: It has been 

 pointed out in a previous paper (1) that the finest 

 structures of this membrane cannot be demonstrated 

 with this technique since they have very little affinity 

 to osmium tetroxide. No certain changes of the 

 basement membrane have been demonstrated in 

 this material. It is possible, however, that it is thic- 

 kened, and that there are structural changes in it, 

 responsible for the increased permeability. 



References 



1. BERGSTRAND, A., Laboratory Invest. (1957, in press). 



2. Kark, R. M. and Muerhcke, R. C: Lancet 1, 1047. 



(1954). 



3. Newman, S. B., Borysko, E., and Swerdlow, M., /. 



Res. Natl. Bur. Stand. 43, 183 (1949). 



4. Palade, G. E., J. E.xptl. Med. 95, 285 (1952). 



5. Rhodin, J., Correlation of Ultrastructural Organization 



and Function in Normal and Experimentally Changed 

 Proximal Convoluted Tubule Cells of the Mouse 

 Kidney. Stockholm, 1954. 



