The Concentration of Adenosinetriphosphate (ATP) Citrate and Calcium in Blood During Insulin Shock Therapy
The blood content of adenosine triphosphate (ATP) and the serum content of citrate and calcium has been studied at various stages before, during and after hypoglycaemic coma and the following observations are recorded:— 

1. In accordance with previous investigators it is found that the curve of inorganic phosphate has fallen by about 30 per cent. two hours after the injection of insulin, but then again moves upwards and has reached normal levels one hour after the termination of coma.

2. The level of ATP is unchanged two hours after insulin injection, but shows a slight increase later.

3. ATP accounts for 80–90 per cent. of the “acid-labile” phosphate fraction. As the concentration of ATP increases, that of the unknown residual component decreases. It is suggested that the residue unaccounted for by ATP may consist partly or wholly of adenosine diphosphate.

4. There is a slight fall of serum citrate during the first phase of hypoglycaemia amounting to about 15 per cent. on the average and a return to normal after termination of coma.

5. There is a fall of serum calcium during hypoglycaemia which is quantitatively small, but statistically significant.

6. The changes are discussed and it is suggested that the drop in citrate concentration may be connected with the changes in phosphate and calcium metabolism rather than with changing levels of other glucose metabolites.