Effects of lithium chloride on testicular steroidogenic and gametogenic functions in mature male albino rats.

The present study was undertaken to evaluate the effects of lithium, an antimanic drug, on steroidogenic and gametogenic functions of testis in the laboratory rat. Adult male rats of Wistar strain maintained under standard laboratory conditions (L:D, 14h:10h), were injected (S.C) with lithium chloride at the dose of 0.1 mg, 0.2 mg and 0.4 mg/100 g body weight/day for 21 days. All the treated animals along with the vehicle treated controls were sacrificed 24 hours after the last injections. Testicular steroidogenic activity was evaluated by measuring the activities of two steroidogenic key enzymes, delta 5-3 beta hydroxysteroid dehydrogenase (delta 5-3 beta-HSD) and 17 beta hydroxysteroid dehydrogenase (17 beta-HSD). Gametogenic capacity was determined by counting the number of germ cells at stage VII of seminiferous cycle. Plasma levels of follicle stimulating hormone (FSH), luteinizing hormone (LH), prolactin (PRL) and testosterone (T) were measured by radioimmunoassay (RIA). Administration of lithium chloride at a dose of 0.1 mg/100 g body wt. for 21 days led to insignificant changes of plasma FSH, LH, PRL and T along with unaltered activities of testicular delta 5-3 beta-HSD, 17 beta-HSD activities and gametogenesis. In contrast, 0.2 mg of lithium treatment for 21 days causes a significant reduction of plasma FSH (P less than 0.01), LH (P less than 0.001), PRL (P less than 0.001) and T (P less than 0.001) along with inhibition of testicular delta 5-3 beta-HSD activity (P less than 0.01) and 17 beta-HSD activity (P less than 0.001). Gametogenic activity does not exhibits any significant reduction in the number of preleptotene spermatocytes (PLSc) and midpachytene spermatocytes (mPSC) while significant reduction in the number of spermatogonia A (Asg) (P less than 0.01) and Step 7 spermatids (7Sd) (P less than 0.001) were observed at stage VII of seminiferous cycle when compared to control. The degree of detrimental effects of lithium on testicular activity became more prominent at the dose of 0.4 mg/100 g body wt. The results of our experiments suggest that lithium administration might be associated with significant adverse effects on testicular activities. Furthermore, since hormonal changes and altered gametogenic activities were evident when plasma lithium concentration was below or within the therapeutic range, our data may have some potential clinical implications.