Abstract
N-L and CLL-L prior to cell culture gave evidence of high activities of TdR phosphorylase, TMP and TDP kinases, while TdR kinase and phosphatase activities were relatively low. Cells cultured without PHA showed no appreciable alteration in enzyme activities during three to five days of culture. Response to PHA with blast-cell formation in cultures of N-L or CLL-L (low-count cases) was associated with increased TdR kinase activity which became prominent at the time of increased DNA polymerase activity and DNA synthesis during the second to third day of culture. Cells from cases of CLL-L with high WBC counts which failed to respond to PHA showed no increase in TdR kinase activity but did show increased phosphatase activity. Increased TdR activity and increased DNA polymerase activity may both be needed for increased synthesis of DNA to occur in lymphocytes responding to PHA.
