Cadmium-induced testicular damage in a rat model of subchronic intoxication

Background: Cadmium (Cd)-induced testicular damage in relation to spermatogenesis has not been well studied. We studied the mechanism of Cd-induced testicular damage in a rat model of subchronic intoxication. Methods:  Male Sprague-Dawley rats were subcutaneously injected with 0.6 mg Cd/kg per day for 6 weeks. The concentration of Cd in urine, serum and testes was measured by using atomic absorption spectrophotometry. Testicular damage was evaluated by counting the spermatogonia (SG) and spermatocytes (SC) on one cut-surface of five seminiferous tubules in stages VII or VIII of spermatogenesis every week. The location of intratesticular cadmium was determined by using oxine-fluorescent cytochemistry. Results: There were no differences in the testes/bodyweight ratio between the study and control groups. The concentration of Cd in the testes increased more than 100-fold that in serum after week 2, suggesting active testicular Cd accumulation (1-3 mg/g tissue). Cadmium accumulation was detected in SG and SC. The number of SG and SC diminished significantly in the study group (week 2: SG 74%, SC 90%; week 4: SG 47%, SC 75%; week 6: SG 30%, SC 54% of the control, respectively). Conclusions: Cadmium accumulated in SG and SC, consequently reduced the number of these cells, and disturbed the spermatogenesis in this rat model of subchronic Cd intoxication. Therefore, the number of SG decreased in this rat model of subchronic Cd intoxication. (Reprod Med Biol 2002; 1: 59-63).