Apparent peroxide ('pro-blue') in organs of irradiated and alarmed mice.

Summary1. An improved anoxic box for estimating apparent peroxide (‘pro-blue’) in whole mice and mouse organs is described.2. The increase in pro-blue in whole mice given 5000 r was still significant despite the more rigorous exclusion of air during extraction.3. In four organs of mice given 5000 r (epididymal fat, lungs, muscle and skin) a significant increase of pro-blue was found. The mean total pro-blue in all organs, plus that in the residual carcass, was about 60 per cent of the mean in whole mice.4. Whole mice given 1000 r and macerated with n-butanol in air did not show a significant increase in pro-blue. The means for both control and experimental mice were higher than normally found with maceration in N2.5. Mild alarm caused a significantly-increased pro-blue in the epididymal fat of males and in the ovarian fat of females. It is suggested that this may provide a mechanism for environmental effects on fertility.