Reversibility and time-dependency of contrast medium induced inhibition of 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide (MTT) conversion in renal proximal tubular cells in vitro: comparison of a monomeric and a dimeric nonionic iodinated contrast medium.
OBJECTIVE
To evaluate the time-course and reversibility of toxicity of a low-osmolar and an iso-osmolar radiographic contrast medium on renal tubular cell cultures.


METHODS
LLC-PK1-cells were incubated with iomeprol, iodixanol, and mannitol (4.7-75 mg I/mL, 2-24 hours). Metabolic activity was assessed with 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide-(MTT) assay.


RESULTS
Iomeprol and iodixanol induced a time- and dose-dependent inhibition of MTT conversion (75%-19% and 70%-23% of control for iomeprol and iodixanol, respectively, at concentrations ranging from 4.7 to 75 mg I/mL after an incubation time of 2 hours and 64%-14% and 65%-12% of control after 24 hours). The mannitol induced inhibition of the MTT conversion was significantly weaker than that induced by iomeprol (99%-47% of control at concentrations corresponding to 4.7-75 mg I/mL after an incubation time of 24 hours, P < 0.001). After 24 hours incubation with iomeprol, iodixanol, or mannitol and a recovery time of 2 hours after removal of the test-solutions, there was only a small inhibition of MTT-conversion (89%, 88%, and 95% of control at 75 mg I/mL).


CONCLUSIONS
Contrast medium induced cytotoxicity consisted of a reversible part and an irreversible part. There was no difference in cytotoxicity between iomeprol and iodixanol over a broad range of concentrations and incubation-times.
Heinrich
Marc
M
Institute of Radiology, University Hospital of Erlangen, Erlangen, Germany. Dr.MarcHeinrich@gmx.de
Scheer
Mario
M
Heckmann
Martina
M
Bautz
Werner
W
Uder
Michael
M
D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D002460:Cell Line; D049109:Cell Proliferation / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D003287:Contrast Media / Q000633:toxicity; D004305:Dose-Response Relationship, Drug; D004847:Epithelial Cells; D007479:Iopamidol / Q000031:analogs & derivatives* / Q000633:toxicity; D007687:Kidney Tubules, Proximal / Q000187:drug effects* / Q000473:pathology*; D013552:Swine; D013997:Time Factors; D014283:Triiodobenzoic Acids / Q000633:toxicity*
D003287:Contrast Media; D014283:Triiodobenzoic Acids; C057937:iomeprol; C044834:iodixanol; D007479:Iopamidol