低渗对比剂剂量对犬肾小管上皮细胞凋亡的作用及对其中Caspase-3表达的影响

目的：研究低渗碘对比剂剂量对犬肾小管上皮细胞凋亡的作用及对其中Caspase-3表达的影响，以期为临床使用低剂量低渗对比剂以降低副反应提供实验依据。材料与方法：家犬静脉高压注射（1.0 mL/s）高、低剂量（分别换算成相当于人用剂量1.5 mL/kg、1.0 mL/kg）碘普罗胺300 mgI/mL，对照组分别给予等剂量生理盐水，注射后48 h取犬肾脏，TUNEL染色检测肾小管上皮细胞的凋亡情况，免疫组化方法观察其中Caspase-3的表达。Western方法半定量检测肾脏髓质中Caspase-3的表达。结果：注射对比剂后肾小管上皮细胞凋亡率及Caspase-3表达较对照组均明显增高（P<0.01），且对比剂高剂量组较低剂量组增高更明显（P<0.01）。结论：临床常用低渗对比剂常规剂量亦能引起犬肾小管上皮细胞凋亡，且与剂量有关，低剂量对比剂可能降低对比剂副反应的发生，Caspase-3可能参与了对比剂诱导肾小管上皮细胞凋亡的调控。

The effect of different doses of hypotonic contrast agent on the dog tubular epithelial cell apoptosis and the expression of Caspase-3

Objective： To study the effect of hypotonic ion-contrast agents dose on the apoptosis of canine renal tubular epithelial cell and the expression of Caspase-3,so that to provide the evidence that low dose of hypotonic contrast agents can help reduce the side effects.Materials and Methods： Different doses（1.5 mL/kg,1.0 mL/kg） of Iopromiden（300 mgI/mL） were injected with high pressure（1.0 mL/s） for dogs in study groups.Control group received an equal dose injection of normal saline.After 48 hours,kidneys were taken out.TUNEL dyeing was done to detect tubular epithelial cell apoptosis,and S-P stain was to observe Caspase-3 expression.Western blot was used to semi-quantitatively observe the Caspase-3 expression in kidney medulla.Results： After injection of contrast agents,tubular epithelial cell apoptosis rate and Caspase-3 expression significantly increased than control group（P0.01）.And the high dose group increased more obviously than the low dose group（P0.01）.Conclusion： Regular doses of hypotonic iodine-contrast agents commonly used in clinics can also cause apoptosis of the dog kidney tubular epithelial cell,which is relative to the dosage.Low dose contrast agents can reduce side effects.Caspase-3 may be involved in the tubular epithelial cell apoptosis controlled by the contrast agents.