Nicotine toxicity to the ultrastructure of the testis in rats

Objective To investigate the influence of nicotine exposure on the ultrastructure of the rat testis. Materials and methods Twenty rats were injected with nicotine at a dose of 0.4 mg/100 g body weight daily for 3 months; a group of 20 control rats matched for weight and age were injected with saline only for the same duration. The testes were then harvested and examined by transmission electron microscopy. Results Rats given nicotine showed: thickening of the tunica propria, caused by an increase in the collagen fibres under the irregular basal lamina; degeneration of junctional specializations between the Sertoli cells, with malformed nuclei showing condensed chromatin; Sertoli cells with numerous polymorphic mitochondria with irregular cristae and an electron-dense matrix. The germ cells were degenerated, spermatids retained excess cytoplasm and accumulated electron-dense lipid droplets in the cytoplasm. The acrosomes were irregular and abnormally configured. Conclusion There were ultrastructural alterations in rats exposed to nicotine that could be attributed to the detrimental effects of nicotine on germ cells, peritubular structures and Sertoli cells.