The effect of X-irradiation on phytohemagglutinin (PHA)-stimulated rat lymphocytes

The effect of X-irradiation on PHA-stimulated rat lymphocytes has been investigated. The animals were exposed to doses of 100 to 800 R. Blood obtained by cardiac puncture was defibrinated and the lymphocytes sedimented by Dextraven. Lymphocytes were separated from supernatant and cultivated for three days in standard medium supplemented with rat serum and PHA. It was found that irradiation reduces the percentage of blast cells in function of the doses of irradiation. This reduction is accompained by an increased number of macrophage-like cells. The labelling index with tritiated thymidine in PHA-transformed lymphocytes was also reduced following irradiation.