CHAPTER VII 



THE INTERNAL SECRETION OF THE KIDNEY 



A BELIEF in some kind of internal secretion on the part of 

 the kidney has existed since the period when interest in the 

 subject was stirred by the researches of Brown-Sequard. We 

 have already seen (p. 25) that some writers have described 

 pressor effects as the result of the injection into animals of 

 extracts made from the kidney. Lewandowsky, however, 

 found that with 5 to 6 centimetres of the blood from the renal 

 vein no more positive result upon the blood-pressure was 

 obtained than with a similar amount of blood taken from any 

 other vein in the body. He concludes that no specific pressor 

 substance is poured out from the kidney by the renal vein. 

 The present writer has frequently tested the effects of different 

 kinds of kidney extracts upon the blood-pressure. Sometimes 

 there is a slight rise of pressure, sometimes there is no rise, 

 or there may be a fall. The rise is never very marked, and 

 only occurs with unboiled ''protein" extracts. The same 

 result may frequently be obtained from extracts made from 

 other organs and tissues, and it may probably be concluded 

 that, so far as the question of internal secretion is concerned, 

 the results are not of any great importance. Further, it may 

 be stated as probable that the high blood-pressure and hyper- 

 trophy of the heart in nephritis bear no relation to the presence 

 of a pressor substance in kidney extracts. 



But arguments based upon experimental work of a different 

 character and upon clinical and therapeutical observations 

 have been urged in favour of the view that the kidneys furnish 

 an internal secretion. Brown-Sequard in 1869, had expressed 

 the opinion that the phenomena of uraemia were not entirely 

 due to the accumulation of urinary constituents in the blood, 

 but to the absence of the normal internal secretion, or, as he 

 expressed it, due to " 1'existence de changements chimiques 



