Rothamsted Symposium on Trace Elements 128 



pounds of the blood and transported to the tissues, including the 

 liver. This was confirmed when we found that the lethal dose 

 of these two salts, intravenously injected, contains, in both cases, 

 the same amount of copper. 



When we experimented with "Ebesal," the lethal dose proved 

 to be higher and the amount of Cu taken up by the liver was 

 greater. 



These experiments, which may explain the results mentioned 

 in Figure 24, seem to indicate a condition of non-saturation of the 

 liver. 



Table 24 : Absorption of radioactive copper by the liver following intravenous 

 injection in calves (in collaboration with E. Havinga and R. BijkerK): — 



Amount of injected 

 Cu recovered from 



the livers 13-7 ± 1.4% 16.1 ± 1.1% 24.5 ± 1.1% 



(0.10 g) (0.09 g) (0.19 g) 



To conclude, we might express the opinion that injection of 

 ionogenic compounds (Cu-acetate) or not too firmly bound com- 

 plex salts (Cu-glycinate) will not make much difference in the 

 pharmacological and therapeutical effects. Compounds which 

 give little or no Cu-ions like "Ebesal" will behave in a different 

 way. As they are less toxic we shall obtain a higher Cu-content 

 of the liver (and probably a lower one for other organs) after 

 injection. 



Ex'periments with horses.— In normal horses, the copper con- 

 tent of the blood serum is somewhat higher than in cattle. Ob- 

 servations made in this laboratory give approximate figures of 

 100-130 micrograms in 100 ml. Horses in foal may show much 

 higher copper values. 



Copper glycinate, repeatedly administered by intravenous in- 



