Age Changes in Renal Function 235 



Landowne and Shock, 1955), as shown in Fig. 8, a portion of 

 the reduction in renal plasma flow must be attributed to a re- 

 duction in total blood flow. However, in experiments to be 

 reported later calculations show that the age reduction in 

 renal blood flow is proportionally greater than the reduction 

 in cardiac output. 



Fig. 7. Change in effective renal plasma flow per unit of diodrast Tm. 

 O O average values. 



(From: Shock,. 1952). 



Other experiments have shown that the reduction of 

 effective renal plasma flow in the aged cannot be ascribed 

 to permanent structural changes in the renal vascular bed 

 (McDonald, Solomon and Shock, 1951). Previous studies have 

 shown that the administration of a pyrogen to young people 



