The Protective Effect of Cysteamine against Genetic Damages by X-Rays in Spermatozoa from Mice

Abstract

of these agents on sex cells of various stages. Kaplan and Lyon (1) made a small test of the possible protective action of cysteamine but found no positive response on dominant lethals in mice. Rugh and Wolff (2) found, however, that cysteamine decreased the sterilizing effect of Xrays in female mice. Wang et al. (3) concluded that injection of cysteamine decreased the transient sterility in irradiated male mice. Mandl (4), studying the number of spermatogonia and pre-spermatocytes in irradiated rats, showed that the reduction was less marked in animals that, prior to irradiation, were given injections of cysteamine. Studies with the same technique as that used by Kaplan and Lyon (1) have been undertaken in order to reinvestigate the effects of cysteamine on the induction of dominant lethals induced in spermatozoa and appearing as post implantation deaths. There were reasons to suspect that agents protecting against somatic damages ought to be effective with regard to genetic damages. In some recent studies, not yet published, Frolen (personal communication) has shown that there is a difference in the rate of dominant lethal mutations induced in spermatozoa from different strains of mice. Furthermore, these strains had previously been studied with regard to their tolerance to acute irradiation. Frolen et al. (5) showed that one of the two strains was extremely sensitive to irradiation (Albino, LD50(30) = 446 r), whereas the other one was very resistant (CBA, LD5o(30) = 748 r). In studies of induction of dominant lethals it was evident that the rate of mutations was higher in the albino than in the CBA strain. Hence, there is an agreement between the sensitivity to somatic damage, as measured by LD5o(30), and the induction of genetic damages in spermatozoa.