An Isotopic Shift of Potassium in Human Bone-marrow and Cancer

Abstract

IN previous investigations it has been found that the isotopic constitution of potassium contained in bone-marrow and tumour tissue from the rat was appreciably different from that of potassium in various other normal rat tissues, the shift observed with 'bone-marrow potassium' being opposite to that observed with 'tumour potassium'. As regards potassium in normal tissues other than bone-marrow, the content of the heavy isotope, ⁴¹₁₉K, usually proved to be very close to that of mineral potassium as contained in ordinary potassium chloride (A.R.) ; only in a few exceptional cases was the ⁴¹₁₉K content slightly decreased^1,3. However, with potassium in bone-marrow (that is, bone including marrow), a marked and regular increase in the content of ⁴¹₁₉K was obtained; on an average, the increase was 1.9 per cent^1,3. This result agreed with earlier findings on potassium in bone-marrow from horse and beef⁴. A similar shift was further obtained with potassium present in rat blood plasma^2,3. On the other hand, potassium in Jensen rat sarcoma showed a distinct decrease of its ⁴¹₁₉K content, and a similar result was found with potassium in mouse sarcoma 37S. The average decrease for both tumours was 1.1 per cent^1,5.