EFFECT OF TUFTSIN ON THE FUNCTIONAL-ACTIVITY AND INTRACELLULAR PH OF MURINE PERITONEAL-MACROPHAGES

The effect of tuftsin and its tripeptide analog in various concentrati ons (from 0.001 to 10.0 mu g/ml) on phagocytosis and on the intracellu lar pH is studied in murine peritoneal macrophages. Tuftsin causes a u niform dose-dependent increase of these two parameters in the cells. T his effect is maximally pronounced at concentrations of the peptide cl ose to its physiological level (about 0.3 mu g/ml) and gradually decre ases as its content in the incubation medium is lowered or raised. On the other hand, the tripeptide analog of tuftsin does not exhibit such an effect on the cells and under the same conditions suppresses phago cytosis and acidifies their intracellular medium.