1912] On the Distribution of Potassium in Renal Cells 389 



ON THE DISTRIBUTION OF POTASSIUM IN RENAL CELLS. 



By C. p. Brown, M.A., 

 Fellow in Biochemistry in the University of Toronto, 1910-11. 



I. Introduction. 



Although investigation of the problems of renal secretion has given 

 us some information regarding the manner in which the kidney carries 

 out its function, it has hitherto thrown very little light on the character 

 of the cellular processes which are fundamentally concerned in the 

 elimination of salts and metabolites from the blood by the renal tubules. 

 This is in large part due to the fact that although our cytological and 

 histological methods are highly developed, yet the results which they 

 give when applied to the kidney do not enable us to understand how a 

 renal cell acts when performing the excretory function. We can by the 

 application of histological and cytological methods distinguish stages in 

 the activity of the cells in the pancreatic and peptic tubules, and we are 

 able to recognize the presence in these cells of the antecedent substances, 

 the zymogens of the ferments which the glands produce. The changes 

 which we distinguish in such gland cells do not give us a very profound 

 view of the processes of cellular secretion involved, for those changes as 

 we observe them are of a more or less superficial character, but in the 

 renal cells the changes which precede, or are consequent on, rest and 

 activity are much less in evidence. It has indeed been claimed that in 

 the active renal cell there are "secretion vesicles" which are not present 

 when the cell is at rest or is relatively inactive, and more or less marked 

 vesiculat ion of the free bolder of the renal cells obtains under the influence 

 of powerful diuretics, but the "secretion vesicles" are held by some to be 

 artefacts, and the vesiculation of the free bordei is not necessarily an 

 indication of the processes which the cell under ordinary conditions 

 undergoes. 



The failure of cytological mechods to reveal fully the cellular pro- 

 cesses of renal excretion has made it necessary to employ other h'nes of 

 investigation on this subject. In the microchemistry of the cell from 

 its inorganic side there are methods some oi which at least are already 

 available for developing to a certain extent a knowledge of these pro- 

 cesses, and it is probable that a full achievement of tliat knowledge will 



