H. BARCROFT, Q. H. GIBSON and D. C. HARRISON 



As a start, the effect of ascorbic acid on the untreated brother was 

 observed. The clinical aspects have been reported 4 . There was a striking 

 change in skin colour of the ear at various intervals after the beginning 

 of treatment. The principal changes in the blood are summarized in 

 Figure 1 . These results were discussed by Barcroft, Gibson, Harrison 



Before 



After Treatment 



Figure 1. 



and McMurray 5 . The decline in MHb concentration in the blood 

 took place comparatively slowly. There was no evidence of increased 

 blood destruction during treatment, and it seemed likely that* re- 

 generation of haemoglobin from MHb was taking place. 



Next, the reduction of MHb by ascorbic acid was investigated 6 . 

 The rate of reaction varied a good deal in different experiments and 

 was increased catalytically by trace metals in the solutions, as well 

 as by the ferri-ferrocyanide system and by some dyestuffs. The reaction 

 appeared to be bimolecular, and was rather slow even with fairly high 

 concentrations of ascorbic acid. Extrapolation from the in vitro results 

 to the concentrations found in the blood of the cases during treatment 

 gave a theoretical rate of MHb disappearance of about the order ob- 

 served in vivo, if it was assumed that dehydroascorbic acid formed 

 during MHb reduction was at once reduced, say, by glutathione, in 

 the red cells. 



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