Subchronic supplementation of lithium carbonate induces reproductive system toxicity in male rat

Lithium is frequently used as an effective drug for the treatment of several psychiatric disorders in human. This alkali element and its salt, at its higher doses, may lead to various side effects or has several toxic effects after prolonged therapeutic use. To test this hypothesis, the present study was designed to investigate the adverse effect of subchronic exposure of lithium carbonate on reproductive organs of male rat. Rats were exposed to lithium carbonate at doses of 500, 800, 1100 mg/kg of diet for 90 days. The weight of reproductive organs, histology of testis, epididymis, seminal vesicle, prostate, testicular interstitial fluid volume (IFV), testosterone level, sperm morphology and fertility index were analyzed. Treatment with higher doses of lithium carbonate (i.e. 800, 1100 mg/kg diet) significantly reduced testes, epididymis and accessory sex organs weights, whereas, lower dose (500 mg/kg diet) did not show any untoward effect. Similarly, the sperm number from cauda epididymis and daily sperm production was significantly decreased with higher doses of lithium carbonate. The serum testosterone levels and IFVs were also reduced significantly. Seminal vesicle and prostate secretions were completely blocked and spermatozoa were not seen in the lumen of epididymis and vas deference. Histological studies have revealed that lithium carbonate (1100 mg/kg) caused degeneration of spermatogenic cells and vacuolization of sertoli cells cytoplasm in the testis. The sperm transit rate and production of abnormal spermatozoa were significantly (P<0.01) increased. When the lithium carbonate-treated males were mated with normal cyclic females, the fertility index declined to 50% even after 30 days of withdrawal of lithium carbonate treatment. These results clearly suggest that subchronic exposure of lithium carbonate promote reproductive system toxicity and reduces fertility of male rats.