Lithium-induced alterations in the testis of the male roseringed parakeet (Psittacula krameri): Evidence for significant structural changes and disruption in the spermatogenetic activity

In this report, we have examined the effects of lithium on testicular morph ology in a male subtropical wild avian species, the roseringed parakeet (Ps ittacula krameri). Adult male birds were collected during the months of Feb ruary-March, a time when the testicular gametogenic activity in these seaso nally breeding birds is at its peak. They were injected, intramuscularly, t wice daily ( 07:00 and 19:00 h) with lithium chloride (Sigma Chemical Compa ny) at a dosage of 0.5 mEq/Kg body weight either for 5 or 10 days. A signif icant decrease in both the absolute and relative testicular weights was evi dent in the lithium-treated birds as compared to those of the saline-inject ed control animals. Light microscopic studies of the testis in the lithium- treated animals showed a wide range of degenerative changes. These included a) a significant reduction in the diameter of seminiferous tubules; b) nec rosis and exfoliation of most of the germ cells in the seminiferous tubular lumen with the exception of the spermatogonia; and c) a significant reduct ion in the number of mature spermatozoa in the tubular lumen. These degener ative changes were dependent on the duration of lithium treatment and were evident when the plasma lithium concentrations were well below the human th erapeutic range. Leydig cell morphology was not affected by lithium however . Our results provide the first experimental evidence of lithium's adverse reproductive function in an avian species. These data provide further suppo rt to the view that lithium adversely affects the male reproductive system and that these effects extend beyond mammalian species.