Kinetics of Haemoglobin in Red Blood Corpuscle 



(non-pregnant 8 ) ram corpuscles has already been referred to in the 

 description of Sir Joseph Bancroft's last morning (p. 30). Clearly 

 there is opportunity for much further work in this direction. The 

 permeability to 2 , as estimated from the dissociation velocity experi- 

 ments, is apparently distinctly higher but is of the same order as the 

 rough average value (i.e. D 2 jD 1 = 0-024) which we have calculated from 

 the early experiments on 2 uptake by sheep haemoglobin solutions 

 and corpuscle suspensions 6 . In these cases, however, the same blood 

 was not used for the suspensions as for the solutions, and hence the 

 calculated value of D 2 jD x is much less certain. 



In concluding this section, we should call attention to two points, 

 wherein caution is required : — 



1 In studying the kinetics of corpuscle suspensions outside the body, 

 it is of course necessary to apply some anti-clotting measure to 

 the drawn blood. In our work, this has usually consisted of 

 defibrination. This probably alters the permeability of the mem- 

 brane from its value in vivo, and at present there is no obvious 

 way of gauging the degree of alteration. It will be a challenge for 

 the future to devise some means of settling this matter, if possible. 



2 Elsewhere in this paper it is shown that the kinetic equation 

 d[XHb]/dt = k' [X][Hb] -fc[XHb] requires modification at high 

 values of [XHb], since the calculated value of k' rises, and that of 

 k, on the other hand, falls. As regards the combination velocity 

 studies, the error due to a rise in k' in the later stages of 

 the reaction must be to some extent compensated by the back 

 reaction term, &[XHb], becoming appreciable. As the latter has 

 been neglected in most of our calculations, it is not improbable 

 that the results obtained on the simpler basis may be reasonably 

 correct. In the dissociation velocity experiments and calculations, 

 the saturation of the haemoglobin should not exceed 80 per cent 

 at the outset, for at saturations below this figure k appears to be 

 sensibly constant. 



Received September 1948 



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6 — Proc. roy. Soc. B 111 (1932) 1 



' — Proc. roy. Soc. 5 115 (1934) 451, 464, 473, 495 



8 Millikan, G. A. Ph.D. Thesis. Cambridge University (1932) 



9 — J.Physiol. 79(1933)152,158 



10 — Proc. roy. Soc. 5 120(1936)366 



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