Abstract
Swelling phenomena of the liver mitochondria were investigated in rats whose whole bodies had been subjected to X-irradiation of 1000R. The rats were killed at 4.5, 6, 17, 22 and 52 hours after irradiation. The rate of swelling of the mitochondria in reaction to various agents decreased after irradiation, reaching its lowest level at 6 hours, but gradually recovering the normal level after 22 hours. Swellings of mitochondria induced by ferrous and ferric ions in a KCl-Tris-HC1 medium were accelerated by X-irradiation, reaching the maximum at 22 hours.
A large amount of lipid peroxide, measured by the degree of formation of thiobarbiturate color matter, was formed in mitochondria treated by ferrous and ferric ions. This formation showed remarkable correlation with the mitochondrial swelling. Irradiation shortened the lag period for the formation of lipid peroxide with Fe2+, as was also observed in the case of mitochondrial swelling.
