Summary
The present experiments pertain to the relationship between radical amount measured by E.S.R. and biological damage of dried Artemia eggs irradiated with γ-rays.
(1) The amount of free radicals increased with the increase of the dose of irradiation; however, the relation was not linear. At the same time, the hatchability rate of the eggs decreased with the exposure dose, producing a sigmoid curve.
(2) The amount of free radicals produced by irradiation in the intact eggs was similar to that in the denuded eggs.
(3) The radical decay was very rapid, immediately after irradiation, then retarded. However, hatchability decreased continuously with time after irradiation.
(4) The hatchability and radical-decay rate of the irradiated eggs stored at 25°c decreased much more rapidly than those at dry-ice temperature.
From these results, it is concluded that decay of free radicals does not imply recover from radiation damage but continues to the point of fixation of the damage.