The Role Of Testicular Enzymes And Sertoli Cell Function Proteins In Cisplatin-induced Testicular Injury In Rats

Objective To investigate the toxic effects and its mechanism of testicular damage induced by cisplatin (CP) through observing the changes of histopathology, sperm motility and viability, testicular enzymes, oxidative stress and Sertoli cell function related proteins in rats. Methods Mature male Wistar rats were divided into four groups including the control group and CP 1.0,2.5 and 5.0 mg/kg groups by intraperitoneal injection for three consecutive days, respectively. Conventional pathological sections of testes were prepared by periodic acid-Schiff staining for histological observation and left epididymis were removed to observe the effects of cisplatin on sperm motility and viability. The detection kits were used to measure the testicular levels of lactate dehydrogenase (LDH), succinate dehydrogenase (SDH), malate dehydrogenase (MDH), acid phosphatase (ACP), alkaline phosphatase (AKP), superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), malondialdehyde (MDA) and total antioxidant capacity (T-AOC) by biochemical assay. Real time-qPCR was used to detect the levels of haemoxygenase-1 (HO-1) and metallothionein-1 (MT-1) mRNA expression. Protein levels of transferrin, vimentin, androgen binding protein (ABP) and inhibinβ-B were analyzed by western blot. Results (1) Compared to the control group, the body weight loss was observed in CP 2.5 and 5.0 mg/kg groups (P<0.01), and the testicular absolute wet weight decreased only in CP 5.0 mg/kg group (P<0.05). The testis-to-whole body weight ratios increased in CP 2.5 mg/kg and 5.0 mg/kg groups (P<0.05 or P<0.01). After periodic acid-Schiff staining, histological observation showed that dosage related changes were appeared in seminiferous epithelium layer, such as the reducing spermatogonia, the irregular cell sparse arrangement, detached germ cells inside the lumen of seminiferous tubules and the thickening interstitial vessel wall. (2) Sperm count and c-level sperm count decreased obviously, d-level sperm count increased significantly in CP 5.0mg/kg group compared with that of the control group (P<0.05). (3) The activities of LDH, ACP and AKP increased significantly in CP 5.0 mg/kg group (P<0.05), but SDH activity was inhibited by CP in all three exposure groups (P<0.01). The level of MDH was significantly different only between CP 5.0 mg/kg group and the control group (P<0.01). (4) The significant increase of MDA was observed, but the activity of SOD decreased in CP 5.0 mg/kg group (P<0.05). The level of T-AOC decreased in all exposure groups (P<0.05). (5) Compared to the control group, the level of HO-1 mRNA significantly upregulated in CP 5.0 mg/kg (P<0.05) and MT-1 mRNA downregulated in all exposure groups (P<0.05). (6) Compared to the control group, the levels of transferrin and ABP decreased in CP 2.5 and 5.0 mg/kg groups (P<0.05), but the levels of vimentin and inhibinβ-B reduced significantly in all CP exposure groups (P<0.01). Conclusion These findings indicated that the inhibited testicular enzymes, enhanced oxidative stress, and down-regulation of Sertoli cell function related proteins play pivotal roles in CP-induced testes damage.