We have confirmed that phytohemagglutinin (PHA) rapidly enhances the uptake of potassium (K+) by human blood lymphocytes. PHA, however, did not produce an increase in lymphocyte K+ concentration. The apparent steady-state of cell K+ concentration despite the marked increase in uptake of 42K+ could be explained by either an increase in K+-K+ exchange or an increase in concentrative (active) K+ a...

W HEN HUMAN LYMPHOCYTES are treated with phytohemagglutinin ( PHA ) , an extract of the kidney bean Phaseolus vulgaris, they undergo morphologic transformation followed by mitosis.13 Cooper and Rubin4 have demonstrated a decrease in the amount of total RNA witin 30 minutes after the exposure of lymphocytes to PHA. This is immediately followed by an exponential increase in the synthesis of RNA w...