Quinine lowers serum and testicular testosterone in adult Sprague-Dawley rats

Abstract

. We have earlier demonstrated that quinine (QU) is a testicular toxicant. This present study was aimed at evaluating the effects of QU on both the serum and testicular levels of testosterone (TT) in an attempt to elucidate o n e of the potential mechanisms of QU-induce d testicular toxicity. Thirty adult male Sprague-Dawley rats weighing 180- 200 g were used and were randomly divided into 3 groups of 10 rats each . Rats in group 1 had distilled water. Rats in group 2 had U only at the dose of 10 mg/k g bod y weight per day (5 day s in a week ) f or 8 weeks. Rats in group 3 rats had 10 mg/k g of Q U (5 days in week ) and 0.05 mg/kg of TT (3 day s in a week ) for 8 weeks. All the animals were sacrificed at the end of 8 week s by decapitation. Seminal analysis was done on the tubular fluid aspirated from t h e caudal epididymides. The two testes were excised, weighed, and volume estimated . One testis of each rat (0.25 g o f tissue) was homogenized with Potassium Chloride and TT level determined in the supernatant of the homogenate, while the other testis was processed f or histology. Morphometry was carried out by assessing the diameter, cross-sectional area , number of profile s p e r unit area , length density a n d numerical density o f t he seminiferous tubules, and t h e relative a n d absolute volume of testicular components. T h e serum levels of TT in all the animals were also determine d at the time of sacrifice. Both the serum a n d testicular levels of TT in rats administered Q U only were significantly (P< 0.001 ) lower than those of t h e control a n d Q U plus TT-treated rats. We conclude that Q U induces spermatogenic epithelial toxicity by possibly interfering with the steroidogenic function of the Leydig cell.