Studies on the characteristics and mechanisms of testicular toxicity induced by Hydroxyurea.

OBJECTIVE: Apoptosis plays a dominant role in both spontaneous spermatogenesis and germ cell death. This study was aimed to investigate the functions of related genes in testicular germ cell death induced by Hydroxyurea (HU). METHOD: Wild-type (WT) and FasL transgenic (TG) DBA/C57BL mice were intraperitoneal injected with 400 mg/kg HU. Twelve hours later, testes were collected. Histomorphology of testis was observed by staining with Periodic Acid Schiff (PAS). Apoptosis was assessed by TUNEL assay. mRNA and protein levels of related genes were evaluated by quantitative RT-PCR and Western blot, respectively. RESULTS: The 2 × 2 factorial design comparative experiments between the WT and TG mice showed that the TG mice exhibited a higher basal apoptotic index. The basal mRNA levels of Fas and FasL and protein levels of Fas, FasL, Caspase-3, Caspase-8 and Caspase-9 in the TG mice were also higher than that in the WT mice. Twelve hours after injection of HU, the testicular tubules exhibited no significantly morphological changes but apoptosis index remarkably increased in both the WT and TG mice, with the latter having the higher amplitude. Although, HU up-regulated the mRNA of apoptosis-related genes, such as Fas and FasL, in both the TG and WT mice, the increased amplitude was more obvious in the TG mice. By Western blot analysis, apoptosis-related proteins Fas, FasL Caspase-3, Caspase-8 and Caspase-9 were significantly increased in both the WT and TG mice, with the TG mice exhibiting a greater up-regulation. CONCLUSION: Germ cell apoptosis induced by the HU treatment may be related to the FasL-mediated signal transduction pathway.

NMR-spectroscopy-based metabonomic approach to the analysis of Bay41-4109, a novel anti-HBV compound, induced hepatotoxicity in rats.

An integrated metabonomics study using high-resolution (1)H nuclear magnetic resonance (NMR) spectroscopy has been applied to investigate the biochemical composition of urine, serum, liver tissue aqueous extracts (acetonitrile/water) and liver tissue lipidic extracts (chloroform/methanol) obtained from control and Bay41-4109 treated rats (10, 50, 400mg.kg(-1).d(-1) for 5 days, i.g.). Principal components analysis was used to visualize similarities and differences in biochemical profiles. The results showed the effects induced by Bay41-4109 at 400mg.kg(-1).d(-1) are different from those induced at 10, 50mg.kg(-1).d(-1). The biochemical profiles of 400mg.kg(-1).d(-1) group might reflect the hepatotoxicity of Bay41-4109 more exactly. The elevation in the level of 3-HB, lactate, 2-hydroxy-acetol and d-glucose was found in the urine, and the levels of VLDL/LDL(CH(2))(n), VLDL/LDL-CH(3), 2-oxo-3-methyl-n-valerate, 3-HB, lactate, acetate, taurine, 2-hydroxy-isovalerate in serum were increased significantly in 400mg.kg(-1).d(-1) group. The predominant changes identified in liver tissue aqueous extracts included an increase in the signal intensities of lactate, 3-amino-isovalerate, pyruvate, choline, trimethylamine-N-oxide (TMAO) and a reduction in the intensities of taurine, hippurate and d-glucose. In liver tissue chloroform/methanol extracts, there was a remarkably increase in many of the lipid signals including the triglyceride terminal methyl, methylene groups, and CH(2)CO, N(+)(CH(3))(3), CH(2)OPO(2), CH(2)OCOR. These observations all provide evidence that fatty acid metabolism disorder and mitochondrial inability might contribute to the hepatotoxicity of Bay41-4109. The application of (1)H NMR spectroscopy to an array of biological samples comprising urine, serum and liver tissue extracts yields new insight into the hepatotoxicity of xenobiotics.