Cell kinetics and radiosensitivity of human lymphocytes stimulated by phytohemagglutinin, Wistaria floribunda or Lentil lectin.

The cell kinetics and the radiosensitivities of human lymphocytes (four donors) exposed to 200 rads of X-rays and stimulated with phytohemagglutinin (PHA), Wistaria floribunda (WFA) or Lens culinaris (LcH-A) extracts have been compared after cultivation times from 42 up to 54 h. All these mitogens are considered activating primarily T lymphocytes. PHA is a tetrameric molecule, whereas WFA as well as LcH-A are dimeric structures having only two reactive sites. PHA displays a higher mitogenic activity than WFA, while LcH-A is much less active than PHA and WFA. After 42 h of culturing, only metaphases of the first mitosis are found, irrespective of the mitogen used. With increasing cultivation times, however, differences in the cell kinetics have been observed for the different mitogens. Furthermore, no differences in radiosensitivity of lymphocytes stimulated by these mitogens were observed when cells are analyzed exclusively in their first mitosis.