Changes of fluoresceindiacetate-hydrolysis and transport in mammalian cells after ultra-violet- and gamma irradiation

Radiat Environ Biophys. 1977 Apr 27;14(1):13-20. doi: 10.1007/BF01331025.


Changes in the permeability of cell membranes and in the enzymatic activity of intact cells and their homogenates after irradiation were studied. CHO-cells, erythrocytes and their homogenates were irradiated with cobalt-gamma radiation and UV-light. It was found that the esterases are more radio-sensitive in intact cells than in the corresponding homogenates. The decrease of the enzymatic activity after irradiation can be described by a one-hit curve, whereas the loss of transport activity can be resolved into two one-hit curves. The slope associated with the more sensitive target mainly determines the course of the composed transport curve. Mechanisms for the decreases in the rate constants are discussed.

MeSH terms

  • Carboxylic Ester Hydrolases / metabolism
  • Carboxylic Ester Hydrolases / radiation effects
  • Cell Line
  • Cell Membrane Permeability / radiation effects
  • Dose-Response Relationship, Radiation
  • Erythrocytes / enzymology
  • Erythrocytes / radiation effects
  • Fluoresceins / metabolism*
  • Gamma Rays
  • Humans
  • Hydrolysis
  • In Vitro Techniques
  • Radiation Effects*
  • Ultraviolet Rays


  • Fluoresceins
  • Carboxylic Ester Hydrolases