COPPER 243 



100 mg was used for intravenous injection. The tissues were digested in 

 HNO3, and the fat extracted with isoamyl alcohol as described in Chap. 5 

 for direct solution counting. With a simihir preparation, 1 to 8 mg cop- 

 per was used for rats, and 7 to 25 mg for ral)bits (Cu-4). The following 

 levels have been employed, mainly using cyclotron-produced Cu*^' (Cu-4) : 

 dogs, 523 to 870 fxc in 39.5 to G2 mg CUSO4 intravenously; human beings, 

 225 /iC in 0.71 mg Cu intravenously; human beings, 75 /ic in 1.22 mg Cu 

 subcutaneously; human beings, 380 nc in 3.79 mg Cu orally; rats and 

 guinea pigs, 5 to 250 juc. 



In a study with chick embryos, cyclotron-produced Cu^^ was prepared 

 in 0.9 per cent saHne containing 150 Mg/ml of copper (Cu-5). One 

 milliliter of solution was injected into the albumen of each egg, since this 

 was found to be the maximum amount that would not cause injury. At 

 no longer than 48 hr after injection, the embryos were removed under 

 warm 0.9 per cent saline, a drop of Bouin's picro-acetic-formaldehyde 

 solution was placed in the live embryo, and then it was dried. Thin 

 cellophane was placed between the embryo and Eastman no-screen X-ray 

 safety film, and a glass-slide sandwich made and held together with spring 

 clips for the exposure. After photographic processing, the autoradiogram 

 was observed in comparison with the dried mounted embryo from which 

 it was taken. 



The metabolism of Cu*^^ in Drosophila was studied by incorporation of 

 the isotope solution into hot fly food. The larvae were washed in Ringer 

 solution before being processed. For whole counts and sectioning, larvae 

 were fixed in hot Formalin-alcohol. For contact autoradiography, larvae 

 were dissected without fixation on dry slides on which the organs w'ere 

 spread and subsequently oven-dried (Cu-6). 



Cii-l. Frierson, W. Joe, Sam L. Hood, Ira B. Whitney, and C. L. Comar: Radiocon- 



taminant.s in Biological Studies with Copper-64, Arch. Biochein. and Biophys., 



38: ;i97-404 (1952). 

 Cu-2. Eden, Alfred, and Henry Hamilton Green: Micro-determination of Copper in 



Biological Material, Biochein. J. London, 34: 1202-1208 (1940). 

 Cu-3. Comar, C. L., George K. Davis, and Leon Singer: The Fate of Radioactive 



Copper Administered to the Bovine, J. Biol. Chem., 174: 905-914 (1948). 

 Cu-4. Copper Metabolism, McCoUum-Pratt Inst. Contrib. 5, pp. 191-215 (1950). 

 Cu-5. Smith, Ellen E., and Peter Gray: The Distribution of Copper^* in Early Embryo 



Chicks, ./. Exptl. ZooL, 107: 183-210 (1948). 

 Cu-6. Poulson, D. F., V. T. Bowen, R. M. Hilse, and A. C. Rubinson: The Copper 



Metabolism of Drosophila, Proc. Natl. Acad. Sci. U.S., 38: 912-921 (1952). 



