Dose-dependent testicular toxicity of propylene oxide in rats induced by repeated intraperitoneal injections

The dose-dependent testicular toxicity of propylene oxide (PO) was evaluated in male Wistar rats when administered by intraperitoneal injections. In 23 mg/kg, 47 mg/kg, and 93 mg/kg groups, PO was given three days a week for six weeks, while PO was given three days a week for two weeks plus once a week after the third week in a 186 mg/kg group. In the 186 mg/kg group, the epididymal weight and sperm count in the body plus tail of the epididymis decreased, while the rate of sperm with morphological abnormalities increased significantly. The number of sperm with an immature head increased slightly, although significantly, even in the 47 mg/kg group and a dose-dependent effect could be seen. The serum testosterone concentration did not change significantly and there were no apparent histopathological changes in Leydig cells in any of the treatment groups. This is the first detailed study concerning the dose-dependent testicular toxicity of PO.