[Effect of thioproline in vitro on selected functions of peripheral blood lymphocytes from healthy persons and patients with lympho- proliferative syndromes].

Thioproline (thiazolidino-4-carboxylic acid) is one of promising antineoplastic preparations arousing interest since several years. In view of controversies with respect to the mechanism of thioproline action it was tried to study the effects of the preparation on certain functions of lymphocytes. The experimental model included cultures of T and B lymphocytes obtained from 20 healthy blood donors. The cultures were exposed to various concentrations of thioproline for determining the incorporation of 3H-thymidine into the DNA of these cells, their viability and intracellular concentrations of cAMP and cGMP. The lymphocytes from these healthy donors served also as a control for B-cells isolated from 24 patients with lymphoproliferative syndromes. It was found that at low concentrations thioproline added to the culture of T-cells from healthy donors caused a slight increase of 3H-thymidine incorporation, but at high concentrations a strong cytotoxic effect on T-cells was noted. B-cells isolated from the peripheral blood of healthy subjects and from the patients were highly sensitive to thioproline. These observations demonstrated a cytotoxic effect of thioproline on T and B lymphocytes.