The Acute Toxic Effects of Cysteamine and Their Modification by X-irradiation

Summary

The toxic effects of cysteamine in mice are described. A dose of just over twice the usual radioprotective dose caused severe convulsions and killed about half the injected animals. The dangers of using this compound in man are discussed.

When a toxic dose of cysteamine was followed by 100 rads of x-rays 2–15 min later, there was a statistically significant reduction in the number of deaths caused by the cysteamine. Doses of 500–5000 rads had no effect on cysteamine mortality. Possible mechanisms are discussed, and a radiation effect on the nervous system is thought to be more likely than a reversal of the protective effect of cysteamine.