毒理性
环氯硝基甲烷(CC)会导致肝脏坏死并具有致癌性质。在体外应用CC于肌细胞会导致肌原纤维的破坏,并在细胞过程中大量积累肌动蛋白、肌球蛋白、α-肌动蛋白结合蛋白和纽蛋白。这种药剂还诱导了肌球蛋白和α-肌动蛋白结合蛋白聚集岛的生成。纤维母细胞中的肌动蛋白丝束要么不受影响,要么完全破坏。CC的损伤程度与剂量相关,且急性给药可逆。通过腹腔注射给大鼠急性给药CC会导致肝细胞变性坏死,揭示肝脏是其特定靶标。CC中毒已被证明会在细胞过程中诱导大量肌动蛋白、肌球蛋白、α-肌动蛋白结合蛋白和纽蛋白的积累。它还诱导了肌球蛋白和α-肌动蛋白结合蛋白聚集岛的大量形成,散布在细胞质中。结蛋白的分布从松散排列的丝网变为紧密排列。细胞质微管保持正常,无法与它们的通常模式区分。因此,CC对肌原纤维和细胞骨架蛋白的影响程度似乎按肌动蛋白、肌球蛋白/α-肌动蛋白结合蛋白/纽蛋白、结蛋白和微管蛋白的顺序排列。这个顺序与蛋白与肌原纤维的肌动球蛋白的接近程度成正比。CC以某种尚未知晓的方式,似乎在解体先前组装的肌原纤维,并形成肌原纤维和细胞骨架蛋白的聚集体。肌原蛋白,尤其是肌动蛋白,在细胞周边的积累是CC处理的特征,但其机制尚需阐明。在CC处理后,纤维母细胞表现出两种不同的反应,即肌动蛋白丝束要么不受影响,要么完全破坏,导致肌动蛋白岛的形成。此外,由CC处理引起的细胞损伤是可逆的。(A15416)
Cyclochlorotine (CC) causes hepatic necrosis and has carcinogenic properties. The in vitro application of CC on myocytes induced disruption of myofibrils and large accumulations of actin, myosin, alpha-actinin, and vinculin at the cellular processes. This agent also induced the formation of islands of myosin and alpha-actinin aggregates. Actin filament bundles in fibroblasts were either unaffected or disrupted completely. CC damage was dose-dependently reversible. Acute administration of CC by intraperitoneal injection to rats caused degeneration and necrosis in hepatocytes revealing that the liver was a specific target. CC poisoning has shown to induce the formation of large accumulations of actin, myosin, _-actinin and vinculin at the cellular processes. It also induces the extensive formation of islands of myosin and _-actinin aggregates, scattered within the cytoplasm. The desmin distribution is changed from a loosely to a densely arranged filament network. Cytoplasmic microtubules remained normal and could not be distinguished from their usual pattern. Thus, the degree of CC influence on myofibrillar and cytoskeletal proteins seems to be in the order of actin, myosin/a-actinin/vinculin, desmin and tubulin. This order is proportional to the proximity of proteins to actomyosin of myofibrils. CC, in some as yet unknown manner, appeares to dismantle previously assembled myofibrils and to form aggregates of myofibrillar and cytoskeletal proteins. The accumulation of myoproteins, particularly actin, at the cellular peripheries was characteristic of CC treatment, but its mechanism remains to be clarified. Two different responses of fibroblasts were noted after CC treatment, i.e., actin filament bundles were either unaffected or were disrupted completely to result in the formation of actin islands. Also, cell damage caused by CC treatment is reversible. (A15416)
来源:Toxin and Toxin Target Database (T3DB)