Protective Effectiveness of Some Sulphur-containing Substances and Oxygen Uptake in the Rat

Summary The protective effectiveness of cysteamine, cystamine, cysteine and beta-mercaptoethanol, has been studied in rats exposed to whole-body irradiation (900 R) at various delays after administration of the compound. Two minutes after the injection of cysteamine or cystamine, the protection is poor; a steep increase of activity is observed between the second and tenth minute. At 20 and 30 min, the effectiveness remains unchanged or drops slightly; the best protection is obtained 45 min after the injection. In this strain of rats, cystamine was more effective than cysteamine. For cysteine, there is also an increase of the activity between 2 and 10 min, but the protection is rather low and remains unchanged from the 10th to the 90th minute. Beta-mercaptoethanol has no protective activity. Cystamine, cysteamine and cysteine decrease the oxygen uptake. The maximum effect is found 10 min after the injection. Later on, there is a progressive recovery of the oxygen utilization. Beta-mercaptoethanol has no depressive effect on the oxygen uptake. The correlation between oxygen uptake and protective effectiveness is discussed.