Goldstein R S, Rickert D E
Chem Biol Interact. 1984 Jun;50(1):27-37. doi: 10.1016/0009-2797(84)90129-7.
Nitrobenzene exposure is known to produce red blood cell damage as well as engorgement and sinusoidal congestion of the spleen in male Fischer-344 (F-344) rats but not in male B6C3F1 mice. These studies were conducted to investigate the species differences in the covalent binding of [14C]nitrobenzene in the erythrocyte and spleen and to assess the contribution of nitrobenzene-induced erythrocytic damage to the splenic effects. Total and covalently bound 14C concentrations in erythrocytes of rats were 6-13 times greater than those of mice following a single oral dose of 75, 150, 200 or 300 mg/kg [14C]nitrobenzene, suggesting that species differences in nitrobenzene-induced red blood cell toxicity may be related to differences in erythrocytic accumulation of nitrobenzene and its metabolites. Covalently bound 14C in erythrocytes of rats peaked 24 h following administration of 200 mg [14C]nitrobenzene/kg; in contrast, bound radiolabel in erythrocytes from mice plateaued at 10 h. Splenic engorgement increased in a time-related manner in treated rats but not in mice. Species specificity was also observed in the accumulation of bound radiolabel in the spleen. Gel filtration and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) of lysed, dialyzed erythrocytes from treated rats revealed that hemoglobin was the primary, if not the exclusive, site of macromolecular covalent binding following nitrobenzene treatment. SDS-PAGE of dialyzed rat spleens revealed that 82% of total bound 14C migrated identically to hemoglobin. These data indicate that covalent binding of [14C]nitrobenzene and its metabolites in the spleen is primarily derived from bound 14C from scavenged erythrocytes. Therefore, the species differences in splenic engorgement and accumulation of [14C]nitrobenzene may be related to differences in susceptibility to nitrobenzene-induced red blood cell damage.
已知接触硝基苯会导致雄性Fischer - 344（F - 344）大鼠出现红细胞损伤以及脾脏充血和血窦充血，但雄性B6C3F1小鼠不会出现这种情况。进行这些研究是为了调查[¹⁴C]硝基苯在红细胞和脾脏中的共价结合的物种差异，并评估硝基苯诱导的红细胞损伤对脾脏效应的影响。单次口服剂量为75、150、200或300 mg/kg [¹⁴C]硝基苯后，大鼠红细胞中总的和共价结合的¹⁴C浓度比小鼠高6 - 13倍，这表明硝基苯诱导的红细胞毒性的物种差异可能与硝基苯及其代谢产物在红细胞中的积累差异有关。给予200 mg [¹⁴C]硝基苯/kg后，大鼠红细胞中共价结合的¹⁴C在给药后24小时达到峰值；相比之下，小鼠红细胞中结合的放射性标记在10小时达到稳定水平。在接受治疗的大鼠中，脾脏充血以时间相关的方式增加，但在小鼠中没有。在脾脏中结合放射性标记的积累方面也观察到了物种特异性。对接受治疗的大鼠裂解、透析后的红细胞进行凝胶过滤和十二烷基硫酸钠 - 聚丙烯酰胺凝胶电泳（SDS - PAGE）分析表明，血红蛋白是硝基苯处理后大分子共价结合的主要（如果不是唯一的）位点。对透析后的大鼠脾脏进行SDS - PAGE分析表明，结合的¹⁴C总量的82%迁移情况与血红蛋白相同。这些数据表明，[¹⁴C]硝基苯及其代谢产物在脾脏中的共价结合主要来源于被清除的红细胞中结合的¹⁴C。因此，脾脏充血和[¹⁴C]硝基苯积累的物种差异可能与对硝基苯诱导的红细胞损伤的易感性差异有关。
