﻿PHARMACOLOGIC AT. ACTION OB^ URANIUM 



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ting will voccur in approximately the normal time. And if the 

 precipitated oalcium and uranium phosphate be washed with a 

 little distilled water, dried and then, after comminution with a 

 little normal salt solution, be added to blood, clotting will occur 

 in about the normal time. It would appear, then, that pure uranium 

 phosphate is sufficiently insoluble in blood to be unable to prevent 

 clot formation. (This also holds good for sodium uranate which 

 is insoluble.) It should be stated that when a solution of disodium 

 hydrogen phosphate is added to a solution of sodium uranium tar- 

 trate the uranium phosphate is not precipitated immediately, but 

 some ten to twenty minutes are required for complete precipita- 

 tion. Consequently, when disodium hydrogen phosphate is added 

 to blood previously treated with uranium it is probable that com- 

 plete precipitation would not occur for some twenty minutes or 

 longer. But if after a period of twenty or thirty minutes either 

 calcium chloride, thrombokinase, fibrin ferment (serum from blood 

 clot) or any two (or all three of these) be added, no clot will be 

 formed. The addition of fibrin ferment would seem to indicate 

 that the fibrinogen had been affected, for if all of the free soluble 

 uranium has been precipitated, tiien the addition of fibrin ferment 

 should produce clotting unless the fibrinogen has been affected. It 

 seems probable, however, that the uranium when first added to the 

 blood rapidly forms combinations with practically all of the pro- 

 teid elements at hand and that even if the excess of free uranium 

 (provided any such cpiantity should be left over) is later precipi- 

 tated out by disodium hydrogen phosphate, then the uranium-pro- 

 teid compounds are not broken up but still maintain practically 

 their original condition. These compounds are apparently also 

 soluble in excess of proteid, for if a small amount (2 cc.) of the 

 blood treated with phosphate, after uranium, be added to a larger 

 quantity (6 cc.) of fresh blood and the mixture well shaken, clot- 

 ting will be prevented. 



It may be objected that in the presence of soluble proteids and 

 dilute salt solutions, such as constitute blood, the disodium hydrogen 

 phosphate would not precipitate out the uranium in the usual man- 

 ner. But if uranium be added to dilute salt solutions approximat- 

 ing as nearly as possible the quantity and cpiality of those found 

 in the blood, then the disodium hydrogen phosphate will precipitate 

 the uranium so completely that the clear filtrate exercises no notice- 

 able inhibitory action upon clot formation in fresh blood. If such 

 precipitate is not formed when uranium, and then phosphate, are 

 added to blood, it would appear to be because the uranium has 



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