Background and objectives: Quinine (QU) has been used worldwide in the suppression and treatment of malaria for more than 350 years. The aim of this study was to determine the long-term morphological response of the testis to long-term administration of QU using stereological parameters.
Materials and methods: 64 adult male Sprague-Dawley rats weighing 180-200g were used. The animals were randomly divided into 8 groups of 8 rats each. Every experimental animal had intramuscular QU at a dose of 10mg/kg body weight per day (5 times in a week, with the exception of group 1 animals). Group 1 rats had QU for 1 week (7 days consecutively) and were sacrificed on the last day of injection. Groups 2 and 3 rats had QU for 4 and 6 weeks and were sacrificed at the end of the 4th and 6th week respectively. Group 4, 5, 6 and 7 rats had QU for 8 weeks and were sacrificed at the end of week 8, 12, 16 and 20 respectively. Group 8 animals constituted the controls and had equal volume of distilled water intramuscularly for 8 weeks. All sacrifices were by decapitation. The testes were carefully dissected out, their volumes measured, weighed and histological sections prepared. Morphometric assessment was carried out using the diameter, cross-sectional area, number of profiles per unit area, numerical density and volume density of the seminiferous tubules and the relative and absolute volume of the seminiferous epithelium, stroma and lumen of tubules.
Results: The results showed that there was a general destruction of cells of the seminiferous tubules and the testicular interstitium that persisted even after the discontinuation of QU and to the end of our experiment that lasted 20 weeks.
Conclusion: We conclude that QU has deleterious effect on the seminiferous tubules of Sprague-Dawley rats, though the mechanism of damage is unclear.