[Protective effect of several diphosphonic compounds against damage to lymphocytes by antilymphocyte serum]

Rabbit antilymphocytic serum and complement were taken in quantities provoking the death of 50 per cent of human lymphocytes secreted in the phycol-verographin density gradient. Compounds (dinatrium salt of oxyethylendiphosphonate acid, alkylated oxyethylendiphosphonate acid, aminoethyloxyethylendiphosphonate acid, aminobenzyldiphosphonate, and aminoisopropyldiphosphonate acids) of 10 mM diphosphonic composition solutions in quantities of from 0.001 ml to 0.2 ml were added to experimental samples of 0.2 ml lymphocytes suspension containing 2.4 X 10(4)--6.0 X 10(4) cells. A decrease in the dead cell count in staining with a 0.1 per cent trypan blue solution was observed. Dinatrium salt of oxyethylendiphosphonate acid and alkylated oxyethylendiphosphonate acid proved to be most effective: it showed protective properties already in a dose of 0.01 ml. All the tested components had a pronounced protective action in a dose of 0.1 ml.