SPECIES DIFFERENCES IN THE IN VITRO SENSITIVITY OF LYMPHOCYTES TO PREDNISOLONE AND X-RAYS

¹ Tumor Research Laboratory, Research and Surgical Services, Veterans Administration Hospital, Hines, Illinois

Lymphocyte suspensions derived from the blood and spleen of mouse, rat, mabbit, guinea pig and man were incubated at 37°C with 10 µml of prednisolone. After a suitable period of incubation, viable lymphocyte counts were made by use of special slide chambers and phase contrast microscopy. Lymphocytes from man and the guinea pig were relatively resistant to prednisolone, and lymphocytes of the mouse, mat and rabbit were sensitive. The lymphocytes from the blood and spleen had the same sensitivity to the reagent except that human lymphocytes of the spleen were slightly more sensitive than blood lymphocytes. Sensitivity to prednisolone had no correlation with sensitivity to X-rays or with the in vitro survival time of the lymphocytes from 5 species. These data suggest that about one-third of human blood lymphocytes are sensitive and two-thirds are resistant to prednisolone. In contrast, nearly all blood and splenic lymphocytes of the mouse and rat are sensitive.