利巴韦林,一种针对丙型肝炎病毒的抗逆转录病毒药物,导致男性生殖毒性。这项研究调查了利巴韦林在血睾丸屏障(BTB)转运的机制。静脉内给药后的体内小鼠整合图分析表明,[3H]利巴韦林在睾丸中的净流入清除率是[14C]D-甘露醇的3.6倍,细胞旁运输标记,意味着利巴韦林跨BTB的跨细胞转运。此外,TM4细胞对[3H]利巴韦林的摄取,小鼠来源的支持细胞,是时间和浓度依赖性的,Km值为2.49mM。S-[(4-硝基苯基)甲基]-6-硫代肌苷,Na+非依赖性平衡核苷转运蛋白(ENT)的抑制剂,在100µM时强烈抑制TM4细胞对[3H]利巴韦林的摄取。与[3H]腺苷的摄取相比,一种典型的内源性核苷,[3H]利巴韦林摄取与ENT2转运相对相似。[3H]利巴韦林的摄取也在小鼠ENT2-表达非洲爪狼卵母细胞中观察到,通过ENT2小干扰RNA转染的基因沉默显着减少了[3H]利巴韦林转运到TM4细胞中的13%。一起来看,这些结果表明,ENT2部分有助于利巴韦林在BTB的转运.
Ribavirin, an antiretroviral agent targeting the hepatitis C virus, causes male reproductive toxicity. This study investigated the mechanism of ribavirin transport at the blood-testis barrier (BTB). In vivo mouse integration plot analysis after intravenous administration revealed that the net influx clearance of [3H]ribavirin in the testis was 3.6-fold greater than that of [14C]D-mannitol, a paracellular transport marker, implying transcellular transport of ribavirin across the BTB. Moreover, [3H]ribavirin uptake by TM4 cells, mouse-derived Sertoli cells, was time- and concentration-dependent, with a Km value of 2.49 mM. S-[(4-nitrophenyl)methyl]-6-thioinosine, an inhibitor of Na+-independent equilibrative nucleoside transporters (ENTs), strongly inhibited the [3H]ribavirin uptake by TM4 cells at 100 µM. Compared to the uptake of [3H]adenosine, a typical endogenous nucleoside, [3H]ribavirin uptake was relatively similar to ENT2 transport. [3H]Ribavirin uptake was also observed in mouse ENT2-expressing Xenopus laevis oocytes, and gene silencing via the transfection of ENT2 small interfering RNA significantly reduced the [3H]ribavirin transport into TM4 cells by 13%. Taken together, these results suggest that ENT2 partially contributes to ribavirin transport at the BTB.