The detection of subchronic testicular damage using urinary creatine: studies with 2-methoxyethanol.

We have previously shown that a number of testicular toxicants administered acutely to rats raise urinary creatine. The aim of this study was to determine if this creatinuria was maintained during subchronic testicular damage. Repeated exposure of rats to 2-methoxyethanol for 10 days administered in the drinking water caused significant testicular damage at the highest dose. The urinary creatine:creatine ratio was significantly increased in the animals receiving the highest dose (220 mg/kg per day) and also those receiving doses of 87 mg/kg per day. Increases in the ratio seen after the lowest dose (43 mg/kg per day) were significant in some cases, but showed more variability. Relative testicular weight was only significantly reduced after the highest dose. Increases in body weight over the time of exposure were only significantly lower after the highest dose of 2-methoxyethanol. The results indicate that urinary creatine may be a useful biomarker for chronic testicular damage.