Phosphorus Exchange in Tissues of Patients with Lymphoid Leukemia. ∗

Abstract

Methods and Materials. Radio-phosphorus (P³²) produced by the Berkeley cyclotron 1 was converted into sodium phosphate for oral and intravenous administration as therapy to patients with leukemia. 2

Small pieces (about 5 g) of tissues obtained at the autopsy of 4 patients so treated were placed in crucibles and ashed at 400°C. The radioactivity of the ashes was measured by means of an ionization chamber. All measurements were calibrated by means of a uranium standard and the activities were corrected for rate of decay of radio-phosphorus (half-life, 14.3 days) to date of death. The total phosphorus (P³¹) content of the ashes was determined by the method of Pregl. 3 By dividing the amount of radioactivity (micro-curies) per gram wet weight of each tissue by the number of milligrams of phosphorus (P³¹) per gram wet weight of the same tissue, one obtains the “specific radioactivity”of the tissue in μc/mg P³¹.

Results. The results are listed in Table I. The notable but anticipated feature is that the “specific radioactivity”of the listed tissues was independent of the variations in type of disease, age of patient, quantity‡ or route of administration of radio-phosphorus, quantity of ingested nonradioactive phosphorus (including that in the diet) and quantity of P³¹ and P³² per gram of a specific tissue, but was apparently dependent upon the time interval between the last dose of radio-phosphorus and death. The quantity of P³¹ in some of the tissues of normal individuals 4 are also recorded in the table.

Discussion. When one contrasts the “specific radioactivities”of Case 4 with those of the other 3 cases it becomes apparent that fairly large amounts of P³² have been retained by the various tissues at the end of the second day after administration.