ISSN:
1432-198X
Keywords:
Ifosfamide
;
Cyclophosphamide
;
Nephrotoxicity
;
Fanconi syndrome
;
Chloracetaldehyde
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Notes:
Abstract Ifosfamide (IF) and cyclophosphamide (CP) are highly effective alkylating cytostatic drugs. IF and CP have to be activated through a metabolic step in vivo; numerous metabolites are known. While both IF and its structural isomer CP have severe urotoxic side effects, only IF is also a nephrotoxic drug, causing tubular damage resulting in Fanconi syndrome in some cases. Little information is available regarding the pathogenic mechanism of tubular damage by IF. We used the renal epithelial cell line LLC-PK1, which has many properties of the proximal tubule, in order to investigate the toxicity of IF and CP and of their reactive metabolites 4-hydroxy-IF (4-OH-IF), 4-hydroxy-CP (4-OH-CP), acrolein and chloracetaldehyde (CAA). Protein content of monolayers, DNA and RNA synthesis were determined by standard techniques (thymidine and uridine incorporation). IF and CP had the lowest toxicities of all compounds tested. Both drugs inhibited thymidine incorporation by about 30% at a concentration of 300 μmol/l after 1 h incubation. 4-OH-IF and 4-OH-CP were significantly more toxic than the parent drugs. Thymidine incorporation, the most sensitive parameter, was reduced by about 70% by 300 μmol/l of either compound. In addition, 4-OH-CP reduced the total protein content of monolayers. 4-OH-IF did not effect protein content and RNA synthesis. Acrolein, the most toxic metabolite tested, reduced all three parameters significantly at concentrations of 50–75 μmol/l after 1 h. Incubation of cells with 100 μmol/l of acrolein showed an effect after only 1 min. CAA significantly damaged monolayers with a reduction of total protein at a concentration of 50–100 μmol/l. Thymidine incorporation was decreased only moderately by CAA, while uridine incorporation was stimulated, which may be interpreted to reflect a mechanism of repair. We conclude that both CP and IF and their metabolites are toxic in renal tubular cells in culture. CAA may play a larger role in the development of renal tubular damage after therapy with IF than was previously recognized.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00865466
