Ionic contrast media induced more apoptosis in diabetic kidney than nonionic contrast media

Contrast-induced nephropathy is a major cause of hospital-acquired acute renal failure, and its risk is significantly increased in patients with diabetes mellitus. This study aimed to examine both the role of apoptosis in low-osmolar contrast media-induced kidney injury in normal and diabetic rats and the difference in the induced kidney injury between ionic and nonionic contrast media.

Normal and streptozotocin-induced diabetic Wistar rats were administered with ionic low-osmolar ioxaglate, nonionic low-osmolar iopromide or normal saline injection. Apoptosis in kidney tubular cells was determined by the presence of positive terminal deoxynucleotidyl transferase-mediated dUTP in situ nick end-labeling (TUNEL) stain.

At 24 hours after administration, both ioxaglate and iopromide injections induced more apoptosis in diabetic (49.7% vs. 25.3% for ioxaglate; 37.7% vs. 25.3% for iopromide; both p<0.001) and normal (36.2% vs. 27.4%, p=0.002, for ioxaglate; 33.6% vs. 27.4%, p=0.029, for iopromide) kidney tubular cells than normal saline injections. Additionally, ioxaglate induced more apoptotic tubular cells in diabetic kidneys than in normal kidneys (p<0.001). Moreover, ioxaglate significantly induced more apoptotic cells than iopromide in diabetic kidneys, but not in normal kidneys (p<0.001, for diabetic rats; p=0.345, for normal rats).

Ionic low-osmolar contrast media induced more apoptosis in tubular cells in diabetic kidneys than in normal kidneys. Notably, ionic contrast media induced more apoptosis than nonionic contrast media in diabetic kidneys.