BACKGROUND/AIMS: This study was designed to investigate the roles of aristolochic acid I (AA-I) and hypokalemia in acute aristolochic acid nephropathy (AAN). METHODS: After an adaptation period (1 week), a total of 40 C57BL/6 mice (male, 8 weeks old) were divided into four groups: I (control group), II (low potassium [K] diet), III (normal K diet with administration of AA-I [10 mg/kg weight]), and IV (low K diet with AA-I). After collecting 24 hours of urine at 2 weeks, the mice were sacrificed, and their blood and kidneys were obtained to perform immunochemical staining and/or Western blot analysis. RESULTS: Proteinuria, glycosuria, and increased fractional excretion of sodium and K were prominent in groups III and IV (p < 0.05). Diffuse swelling and poor staining of collecting duct epithelial cells were evident in the medullas of group II. Typical lesions of toxic acute tubular injury were prominent in the cortices of groups III and IV. Α-Smooth muscle actin (α-SMA) was higher in the cortices of the mice in groups III and IV versus group II (p < 0.05), and higher in the medullas of group IV than groups I and III (p < 0.05). E-cadherin was higher in the cortices of groups III and IV compared to group I (p < 0.05). The F4/80 value was higher in the cortices and medullas of groups II, III, and IV compared to group I (p < 0.05), particularly in the case of group II. CONCLUSIONS: AA-I can induce acquired Fanconi syndrome in the acute stage of AAN. Macrophages appear to play a key role in the pathogenesis of AAN and hypokalemic nephropathy. It remains uncertain whether hypokalemia plays any role in AAN and hypokalemia.
Actins ; Animals ; Balkan Nephropathy ; Blotting, Western ; Cadherins ; Diet ; Epithelial Cells ; Fanconi Syndrome ; Glycosuria ; Hypokalemia* ; Kidney ; Macrophages ; Mice ; Potassium ; Proteinuria ; Rats* ; Sodium

Ochratoxin A is a natural contaminant of mouldy food and feed, which is produced by Penicillium and Aspergillus, and is suspected of being one of the etiological agents responsible for Balkan endemic nephropathy and the associated urinary tract tumors. For evaluation of the mutagenicity of ochratoxin A, we performed in vitro chromosome aberration tests using Chinese hamster lung fibroblast cells (CHL cells) and monkey kidney cells (VERO cells), in vivo micronueleus tests using ddY mouse bone marrow cells and somatic mutation and recombination tests (SMART) using Drosophila melanogaster. The results of chromosome aberration tests in CHL cells showed no incidence of increased structural and numerical aberrations regardless of metabolic activation, while in VERO cells treated with 2.0, 1.0, 0.5, 0.3 ug/ml of ochratoxin A showed significant increase of structural aberrations without metabolic activation. Aspartame and-phenylalanine, structural analogs of ochratoxin A, didn't affect the chromosome aberrations induced by ochratoxin A. The in vivo induction of micronucleated polychromatic erythrocytes were measured in bone marrows of ddY mice treated with 10.0, 5.0, 2.5mg/kg/10ml of ochratoxin A through intraperitoneal route once. At 24 and 48 hours after treatment, ochratoxin A didn't induce micronuclei in bone marrows of ddY mice. And at the concentration of 40, 20, 10 ug/ml of ochratoxin A, which was administered by feeding to larvae of Drosophila melanogaster, showed no incidence of increased multiple wing hairs and flares. Summarizing all results, we concluded that ochratoxin A is a kidney cell specific direct genotoxicant.
Animals ; Asian Continental Ancestry Group* ; Aspartame ; Aspergillus ; Balkan Nephropathy ; Biotransformation ; Bone Marrow ; Bone Marrow Cells ; Chromosome Aberrations ; Cricetinae ; Cricetulus* ; Drosophila melanogaster* ; Drosophila* ; Erythrocytes ; Fibroblasts ; Hair ; Haplorhini ; Humans ; Incidence ; Kidney ; Larva ; Lung* ; Mice* ; Penicillium ; Recombination, Genetic ; Urinary Tract ; Vero Cells*