We investigated the phosphorus turnover of the serum P and of acid soluble phosphorus in Yoshida sarcoma on the 7th day after the transplantation with the aid of P³².
The curve for the time course of the r.s.a. of the serum P dropped along the fomula C=C₁e^-k₁t₁+C₂e^-k₂t₂.
The specific activities of the phosphorus compounds 1 hour after the administration ranged in the following order: inorganic P, labile P of ATP and ADP, glucose-1-phosphate, phosphoglyceric acid, glucose-6-phosphate, adenylic acid and propanediol phosphate.
The precursor of the labile P of ATP and ADP and of glucose-1-phosphate seemed to be the serum inorganic phosphorus.
The r.s.a. of the phosphoglyceric acid of this tumor was relatively higher than that of another tumor.
Turnover of glucose-6-phosphate, adenylic acid, stable P of the ATP and ADP and of coenzyme P were roughly the same.