Am J Vet Res. 2021 Feb;82(2):125-131. doi: 10.2460/ajvr.82.2.125.
To investigate the effects of triamcinolone acetonide (TA) and methylprednisolone acetate (MPA) on the viability of resident cells within the fibrocartilage on the dorsal surface of the deep digital flexor tendon (FC-DDFT) and fibrocartilage on the flexor surface of the navicular bone (FC-NB) of horses.
12 to 14 explants of FC-DDFT and of FC-NB from grossly normal forelimbs of 5 cadavers of horses aged 9 to 15 years without evidence of musculoskeletal disease.
Explants were incubated with culture medium (control) or TA-supplemented (0.6 or 6 mg/mL) or MPA-supplemented (0.5 or 5 mg/mL) medium for 6 or 24 hours. Explant metabolic activity and percentage of dead cells were assessed with a resazurin-based assay and live-dead cell staining, respectively, at each time point. Drug effects were assessed relative to findings for the respective control group.
Application of TA (at both concentrations) did not significantly change the cell viability of FC-DDFT explants. For FC-NB explants, TA at 6 mg/mL significantly reduced the metabolic activity and increased the percentage of dead cells at both time points. With either MPA concentration, FC-DDFT and FC-NB explants had reduced metabolic activity and an increased percentage of dead cells at 24 hours, whereas only MPA at 5 mg/mL was cytotoxic at the 6-hour time point.
In ex vivo explants, TA was less cytotoxic to equine FC-DDFT and FC-NB cells, compared with MPA. Further work is warranted to characterize the drugs' transcriptional and translational effects as well as investigate their cytotoxicity at lower concentrations.
研究曲安奈德（TA）和醋酸甲泼尼龙（MPA）对马深屈肌腱背侧纤维软骨（FC-DDFT）和跗骨屈肌腱纤维软骨（FC-NB）固有细胞活力的影响。
5 匹 9 至 15 岁无骨骼肌肉疾病大体正常马的前肢 12 至 14 个 FC-DDFT 和 FC-NB 节段。
将节段置于含培养基（对照）或 TA 补充（0.6 或 6mg/ml）或 MPA 补充（0.5 或 5mg/ml）培养基中孵育 6 或 24 小时。分别采用基于 Resazurin 的测定法和死活细胞染色法评估节段代谢活性和死亡细胞百分比，每个时间点均与相应的对照组进行比较。
TA（两种浓度）的应用均未显著改变 FC-DDFT 节段的细胞活力。对于 FC-NB 节段，6mg/ml 的 TA 在两个时间点均显著降低代谢活性并增加死亡细胞百分比。两种 MPA 浓度下，FC-DDFT 和 FC-NB 节段在 24 小时时代谢活性降低，死亡细胞百分比增加，而只有 5mg/ml 的 MPA 在 6 小时时具有细胞毒性。
在体外节段中，与 MPA 相比，TA 对马 FC-DDFT 和 FC-NB 细胞的细胞毒性更小。需要进一步研究以表征药物的转录和翻译效应，并研究其在较低浓度下的细胞毒性。
