92 



Physiology of the Kidney 



FIGURE 7 



Figure 7. The eflfective renal plasma flow (D), filtration rate (IN), tubular ex- 

 cretory mass (D-Tm) and filtration fraction (FF) in 15 subjects with benign hyperten- 

 sion. The data are fully discussed in the text. 



The first impressive fact in these data is that here is a 

 disease which probably from its onset progressively destroys 

 the renal parenchyma. Apart from advanced malignant 

 nephrosclerosis it is impossible to predict from the usual clin- 

 ical evidence or the patient's history whether the renal par- 

 enchyma will be found to be essentially intact or reduced to 

 50 to 40 per cent of its normal value. As yet in no individual 

 with hypertension have we found diodrast-Tm equal to 

 the average normal value, and in only the first three subjects 

 at the left does it exceed the lowest observed normal value. 

 Yet it is possible that these three subjects have suffered some 

 pathological reduction in tubular excretory mass. 



Secondly, in no single individual have we ever found a 



