IN VITRO INCORPORATION OF 3H-THYMIDINE 3H-URIDINE 3H-LEUCINE AND 3H-MELPHALAN BY PLASMACYTOMA PLASMA CELLS

Bone marrow plasma cells from fifteen cases of multiple myeloma, immunologically typed, were incubated with different tritiated compounds. The labelling index with tritiated thymidine is generally low, while the mean grain count is fairly normal in the active cells. The labelling index of 3H‐uridine and 3H‐leucine was very high, while the mean grain count per cell lies within the normal range. The results obtained with 3H‐phenylalanine‐mustard (melphalan), which is a drug used in the treatment of the plasmacytoma, show also incorporation values roughly comparable to those of 3H‐leucine. The present data seem to support the clinical use of melphalan as a compound that is actively incorporated into the plasma cells of plasmacytoma although inhibition of protein synthesis due to specific binding to protein was not demonstrated. Copyright © 1969, Wiley Blackwell. All rights reserved