F. J. W. ROUGHTON, J. W. LEGGE and P. NICOLSON 



amounts of choleglobin 12 or cruoralbin 13 . The reduced Hb-Na 2 S 2 4 

 mixture, in the same experiment, showed no choleglobin (as judged by 

 the appearance of a band in the red at 620-630 xn.fi, when the mixtures 

 were treated with CO-saturated, buffered Na 2 S 2 04). We have no 

 explanation as to why this reaction occurred to such variable extents, 

 but the correlation between it and the apparent ' plateau ' was striking. 

 In our final pair of experiments (9 and 10 March 1948) choleglobin 

 formation and a ' plateau ' at ca 18 per cent O a Hb were seen on the 

 first day, but on storing the blood overnight both these effects were 

 found next day practically to have disappeared. The apparent high 

 * plateaux ' may thus be, in large measure, artefacts due to the effect 

 on the photo-colorimetric readings of the development of pigments 

 other than 2 Hb or reduced Hb. At present, therefore, we do not feel 

 that we can be sure of the presence of appreciable amounts of oxy- 

 hemoglobin during the apparently high ' plateau ' periods, and 

 unless independent evidence in favour of it is secured, preferably by 

 gasometric rather than by optical methods, it would not be profitable 

 to discuss further the possible bearing of the apparent diphasic dis- 

 sociation at neutral pH on other properties of haemoglobin. Although 

 this work, on which we have spent much time and energy, has been 

 disappointing, we have thought it well to report it in some detail in 

 view of the wide use of Na 2 S 2 4 for studying the dissociation of oxy- 

 haemoglobin and other oxygen-carrying pigments. It is a pity that no 

 alternative O a -absorbing agent has been, or is at present, available 

 with which to compare the results obtained with Na 2 S 2 4 at neutral 

 pH, valuable and in many ways satisfactory though this reagent has 

 been. 



THE KINETICS OF HAEMOGLOBIN IN THE 

 RED BLOOD CORPUSCLE 



The first measurements on the rate of combination of haemoglobin in 

 the intact red blood corpuscle with 2 and CO were made by Hartridge 

 and Roughton 4 . Later and rather more accurate results, including also 

 data on the rate of dissociation of carboxyhaemoglobin and oxy- 

 haemoglobin in the corpuscle, were subsequently obtained 7 ' 14 » 15 . 

 Table II gives a summarized comparison of the various reactions, 

 measured under comparable conditions for adult sheep haemoglobin, 

 in the red blood corpuscle and in homogeneous solution (blood 1 in 

 60 about). It will at once be noted that the reactions in the corpuscle 

 take longer than in solution, except the very slow dissociation of 

 carboxyhaemoglobin. 



74 



