54 



Paul Fourman and Patricia M. Leeson 



reduced excretion of solutes. The rate of excretion of sodium 

 and of solutes was actually higher than with dehydration, 

 though lower than immediately before the pitressin was 



Table III 



Effects of pitressin in the two patients while their 

 hydration was maintained 



Changes in urine and plasma Albert Ivor 



Maximum urine concentration (m-osm./l.) 280 387* 



Flow at maximum concentration (ml./min.) 1-5 2-4 



[Na] ([z-equiv./ml. of urine) 33-2 60-2 



Plasma (m-osm./l.) 233 243 



* The results on the first collection (see Fig. 2) have been neglected. 



given. Glomerular filtration rates were not measured. The 

 same batch of pitressin was shown to have normal activity 

 in other subjects. 



Min 



DEHYD^ 



1////////////77ZZ 



PITRESSIN 



3^- 



DEHYD^ 



PITRESSIN 



"'"^'ff /'^TTTfc-»— 



PLASMA 



TIME 8 9 10 II 12 



7JULY 



12 13 14 15 16 



ALBERT '""" 



9 lO II 

 7 JULY 



2 12 13 14 15 16 VI 



IVOR '^"" 



Fig. 2. Comparison of the changes in the flow and concentration of urine 

 following deprivation of water and following pitressin and a water load. 



The difference between the effects of water deprivation and 

 pitressin is far greater than anything observed in normal 

 people (Jones and de Wardener, 1956), and indeed indicates 

 an almost complete failure to respond to pitressin in the 



