CARBON MONOXIDE CAPACITIES 485 



this disease does not explain this finding, and no normal blood of the newborn 

 was studied. 



There is no doubt that in some anemias the nonhemoglobin iron is greatly 

 increased {741,1417). While Jenkins and Thomson concluded, from the low 

 nonhemoglobin iron values often found in recovery from anemia, that young 

 erythrocytes contained a smaller nonhemoglobin iron content than the 

 average, Burmester {3S3) found very high nonhemoglobin iron values in 

 immature turkey and chicken erythrocytes. This difference is perhaps due 

 to the fact that bird blood contains nucleated red cells. 



5.3. Differences between Carbon Monoxide Capacities 

 before and after Reduction 



These differential estimations are a measure of all ferric hematin com- 

 pounds which are reducible to ferrous heme compounds and may be present 

 in the blood, such as ferrichojeglobin, sulfhem/globin, verdohemjchromes, 

 but also hem/globin. Carbon monoxide capacity in the presence of dithionite 

 is estimated by the method of Van Slyke and Hiller {2573; also 2141, p. 349); 

 the gas capacity without reduction can be measured as either carbon monoxide 

 or oxygen capacity. 



A difference between carbon monoxide capacities with and without reduc- 

 tion was first observed by Klumpp {looO) in 1935. It was confirmed by 

 Taylor and Coryell {27 4^) and particularly by Ammundsen {47-49)- The 

 difference for healthy humans varied from to 14.5%, with an average of 

 3.5%; in two thirds of all cases the difference was below 5% and in only a 

 few, above 10%. The close agreement of the average figure with Barkan's 

 figure for "easily detachable iron" in blood is certainly accidental, since the 

 larger part of the latter is, as we saw. derived from oxyhemoglobin; these 

 results were later confirmed by several workers. Nevertheless, it is not yet 

 quite certain whether the difference is not, at least partially, due to inaccu- 

 racies in analytical procedure. Thus Kallner {145S) explains the results of 

 Ammundsen on the basis of insufficient saturation with carbon monoxide in 

 the estimation without reduction by the method of Van Slyke and Hiller. 



Similarly Ramsay {2202) at first found large differences between oxygen 

 capacity before and after titanous citrate reduction (Conant's method, 

 480), but later showed that these largely disappeared with more efficient 

 oxygenation. 



In comparing carbon monoxide capacity after reduction with oxygen 

 capacity of lalood one has to bear in mind the possibility that ferricyanide 

 may not develop the oxygen from oxyhemoglobin quantitatively in the 

 presence of certain substances in the plasma {cf. Chapter VIII, Section G.3.G.; 

 141 ',49) So far, no differences between oxygen and cari)on monoxide capac- 

 ities (without reduction) have been found (2 'j3 1,2 53 2, 2 57 2), but the agree- 

 ment might be accidental, if the carbon monoxide method also gives too low 

 values. 



How great a part of any difference between the carbon monoxide capacities 

 before and after reduction can be ascribed to hem/globin is still a matter of 

 dispute. Differences as high as 10 to '^0% of the total capacity have been 



