Effect of catecholestrogens on mortality and liver lipid peroxide level of mice irradiated with super(60)Co gamma -ray

When 10 weeks old male BALB/c mice received wholebody irradiation with an 8-Gy single dose of super(60)Co gamma -ray, the survival rate 30 days after the irradiation was only 5%, while the survival rate was increased to 70% when the mice were subcutaneously injected with catecholestrogen 2-hydroxyestradiol (2-OHE sub(2)) 3 h before and 3 h after the irradiation. The survival rates of the mice given other test compounds were as follows: 2-hydroxyestrone, 20%; 2-hydroxyestriol, 20%; 4-hydroxyestradiol, 0%; 2-methoxyestrone, 0%; 2-methoxyestradiol, 0%; 2-methoxyestriol, 0%; estrone, 0%; estradiol, 5% and estriol, 20%. Upon the irradiation, lipid peroxide levels in the liver of the animals markedly increased 4 days after the irradiation. This increase in the level was significantly suppressed by the subcutaneous injection of 2-OHE sub(2). These results indicate that 2-OHE sub(2) has a protective effect against radiation injury.