Radiation protection of male fertility in mouse and rat by a combination of 5-hydroxy-L-tryptophan and a thiol compound (AET).

Sperm abnormalities and fall in total sperm count following different doses (4 Gy, 5 Gy and 6 Gy) of whole body gamma irradiation (WBGR) were studied in adult male Swiss strain A mice. The protecting ability of a combination of 5-hydroxy-L-tryptophan (5-HTP, 100 mg/kg) and 2-aminoethyl isothiuronium bromide hydrobromide (AET, 20 mg/kg) was also investigated. Pretreatment with a 5-HTP+AET formulation i.p., 30 min before irradiation modified the fall in sperm counts significantly. Exposures to 4 Gy, 5 Gy and 6 Gy WBGR caused marked increase of sperm abnormalities which could be significantly reduced by pretreatment with 5-HTP-AET. WBGR with 4 Gy, 5 Gy and 6 Gy produced a short period of sterility associated with oligospermia but these abnormalities were corrected by pretreatment with 5-HTP+AET. This finding was supported by breeding experiments in pretreated adult male Sprague-Dawley rats which showed delivery of normal offsprings in drug-protected irradiated groups in contrast to irradiated controls.