408 HERMAN O. MOSENTHAL 



present as in double nephrectomy the reflex can not be elicited. (It 

 should be noted, however, that there may be a slight rise in blood pressure 

 under these circumstances, as in Janeway's case, in which the blood pres- 

 sure rose to 180 after extirpation of the only remaining kidney.) 



Volhard cites the fact that in focal nephritis and in the nephroses, that 

 is when there are sufficient glomeruli intact to allow the blood to pass 

 through the kidney freely, there is no rise in the blood pressure. On the 

 other hand, in acute, subacute and chronic diifuse nephritis the narrowed 

 lumina of the glomerular capillaries set up a reflex that stimulates the 

 arteries to increased tone and results in raising the blood pressure. The 

 hypertension is thus regarded as a compensatory phenomenon to induce 

 an adequate renal circulation. Such an explanation is identical with 

 that held twenty years ago and which has not proved to be entirely satis- 

 factory, inasmuch as it has not been found that renal function is modified in 

 any way as the blood pressure varies. The studies that have been made on 

 patients whose systolic pressure changes a good deal amply bears this out. 



There are certain other facts with which this theory is not in accord. 

 In amyloid disease, in passive congestion, with partial occlusion of the 

 renal veins by pressure or otherwise, and in some instances of arterio- 

 sclerotic kidney (as previously mentioned) the blood pressure rises slightly, 

 if at all, yet in all of these glomerular circulation should be impeded. 

 Furthermore, the condition, characterized by the most marked degrees 

 of blood pressure, shows in its early stages at least a normal renal struc- 

 ture. It is certain that in this condition, essential hypertension, Volhard's 

 Iheory can not be applied; whether or not it holds true for the other 

 types of hypertensive disease can not be denied, though it seems improbable 

 that it should. 



To what different conclusions a clinician and pathologist may arrive 

 at is illustrated by the deductions which Ophiils draws from his patho- 

 logical material. He found in a series of avitopsies showing chronic glom- 

 orulonephritis that there were more instances of low blood pressure and 

 small hearts among the cases with the most extensive destruction of renal 

 tissue than among those in which the renal lesion was less marked. 



Summary 



An increased arterial pressure may occur in any form of Bright's dis- 

 ease ; it may be absent in any of them. It is more common in the acute, 

 subacute and chronic diffuse cases of nephritis than in the degenerative 

 lesions or nephroses in which it does not appear frequently. The most 

 marked instances of hypertension are those characteristic of the malady 

 called essential hypertension, in which the kidney lesions (arteriosclerosis) 

 are secondary to the increased blood pressure, and not primary. In fact 



