The Renal Blood Flow 1 1 



is typically characterized by renal ischemia and impairment 

 of tubular function leaves less reason than ever to divide 

 renal and essential hypertension into two entirely indepen- 

 dent categories. It would be easy to jump to the conclusion 

 that the kidneys are the primary locus of pathology in every 

 case, and to believe that renal ischemia, by initiating tubular 

 injury, accelerated the formation or absorption of the Gold- 

 blatt hypertensive principle which, by reacting on the renal 

 arterioles, induced further constriction in the renal vascular 

 bed and thus contributed to a gradual but vicious cycle of 

 ischemic renal destruction. 



But before accepting this conclusion, we must note that 

 the Goldblatt principle has not as yet been shown to produce 

 in the human kidney the specific circulatory disturbance 

 which is characteristic of the disease ; neither has it as yet been 

 demonstrated that the Goldblatt principle, when allowed to 

 act over a long period of time, can produce the destructive 

 changes which are observed in the disease; nor can it be ex- 

 plained, without invoking too much hypothesis at the present 

 time, how the primary renal ischemia is initiated. If we are 

 to attach little or no significance to these gaps in the logical 

 chain' then tremendous responsibility must devolve upon the 

 kidneys, a responsibility which I cannot describe better than 

 by quoting from the pathologist, Jean Oliver,"^ who in dis- 

 cussing the so-called "normal" senescence of man, says: 



''As a part of the senescent process there develops a gen- 

 eralized sclerosis of the smaller arteries. Other factors for- 

 tuitous or 'pathological' may influence the course of the vas- 

 cular alteration, but with this we are not at present con- 

 cerned. The vascular change within the various tissues and 

 organs may be severe, but there is no evidence that compels 



