Egerbacher M, Wolfesberger B, Gabler C
Institute of Histology and Embryology, University of Veterinary Medicine, Vienna, Austria.
Vet Pathol. 2001 Mar;38(2):143-8. doi: 10.1354/vp.38-2-143.
Quinolones and magnesium deficiency cause similar lesions in joint cartilage of young animals. Chondrocytes cultivated in the presence of quinolones and in Mg-free medium show severe alterations in cytoskeleton and decreased ability to adhere to the culture dish. We investigated whether Mg2+ supplementation can prevent quinolone-mediated effects on chondrocytes in vitro. Chondrocytes cultivated in Dulbecco's modified Eagle's medium/HAM's F-12 medium were treated with ciprofloxacin (80 and 160 microg/ml) and enrofloxacin (100 and 150 microg/ml). Mg2+ was added at a concentration of 0.0612 mg/ml (MgCl) and 0.0488 mg/ml (MgSO4) or a triple dose. In addition, cells were cultivated in Mg-free medium and accordingly treated with Mg2+ supplementation. After 5 days in culture, the number of adherent cells per milliliter was determined. The number of chondrocytes in quinolone-treated groups decreased to 12-36% that of the control group within the culture period. With Mg2+ supplementation, the number of attached cells increased to 40-70% that of control cells. The threefold dose of Mg2+ led to better results than did the single dose. Cell proliferation tested by immunohistochemical staining with Ki67 (clone MIB5) decreased from 70% in control groups to 55%, 48%, and 30% in enrofloxacin-treated groups in a concentration dependent manner (50, 100, and 150 microg/ml). Addition of Mg2+ did not increase the rate of cell proliferation. These results suggest that a great part of quinolone-induced damage is due to magnesium complex formation, as Mg2+ supplementation is able to reduce the effects in vitro. However, quinolone effects on cell proliferation seem to be an independent process that is not influenced by magnesium supplementation.
喹诺酮类药物和镁缺乏在幼龄动物的关节软骨中会导致相似的损伤。在含有喹诺酮类药物的环境以及无镁培养基中培养的软骨细胞，其细胞骨架会出现严重改变，并且黏附于培养皿的能力下降。我们研究了补充镁离子是否能够在体外预防喹诺酮类药物对软骨细胞的影响。在杜氏改良 Eagle 培养基/哈姆氏 F-12 培养基中培养的软骨细胞，分别用环丙沙星（80 和 160 微克/毫升）和恩诺沙星（100 和 150 微克/毫升）进行处理。分别以 0.0612 毫克/毫升（氯化镁）和 0.0488 毫克/毫升（硫酸镁）的浓度或三倍剂量添加镁离子。此外，细胞在无镁培养基中培养，并相应地进行镁离子补充处理。培养 5 天后，测定每毫升贴壁细胞的数量。在培养期间，喹诺酮处理组的软骨细胞数量降至对照组的 12% - 36%。补充镁离子后，贴壁细胞数量增加至对照细胞的 40% - 70%。三倍剂量的镁离子比单剂量产生的效果更好。通过 Ki67（克隆 MIB5）免疫组织化学染色检测的细胞增殖，在对照组中为 70%，在恩诺沙星处理组中（浓度分别为 50、100 和 150 微克/毫升）以浓度依赖方式降至 55%、48%和 30%。添加镁离子并未提高细胞增殖速率。这些结果表明，喹诺酮诱导的损伤很大一部分是由于镁络合物的形成，因为补充镁离子能够在体外减轻这些影响。然而，喹诺酮对细胞增殖的影响似乎是一个独立的过程，不受镁补充的影响。
