Changes in urinary and renal tubular enzymes caused by subchronic administration of ochratoxin A in rats.
The activities of 5 enzymes in urine and renal tubules were measured after administration to male Wistar rats of small doses of ochratoxin A (145 micrograms/kg per day for 8-12 weeks, corresponding to 2 ppm in the feed) by intubation. These doses are in the range of natural contaminations found in food and feed. The enzymes examined were gamma-glutamyl transferase (gamma-GT), alkaline phosphatase (ALP), leucine aminopeptidase (LAP), lactate dehydrogenase (LDH), and N-acetyl-beta-D-glucosaminidase (NAG). The doses employed caused increased enzymuria and lower activities of tubular enzymes after 1 week of feeding. This suggests tubular injury. The change of the enzyme activities in the urine and in the tubules appeared in a cyclic way (degeneration and regeneration). Phenylalanine (20 ppm) partially prevented this action of ochratoxin A. The p-[14C]aminohippurate accumulation was inhibited by 60% in the second week but returned to almost normal level 6 weeks after the beginning of the treatment, suggesting an adaptation of the organism or a substitution of damaged cells.
D000118:Acetylglucosaminidase / Q000652:urine; D000469:Alkaline Phosphatase / Q000652:urine; D000818:Animals; D007672:Kidney Cortex / Q000378:metabolism; D007684:Kidney Tubules / Q000187:drug effects* / Q000201:enzymology; D007770:L-Lactate Dehydrogenase / Q000652:urine; D007931:Leucyl Aminopeptidase / Q000652:urine; D008297:Male; D009793:Ochratoxins / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains; D005723:gamma-Glutamyltransferase / Q000652:urine; D010130:p-Aminohippuric Acid / Q000378:metabolism
D009793:Ochratoxins; C025589:ochratoxin A; D007770:L-Lactate Dehydrogenase; D005723:gamma-Glutamyltransferase; D000469:Alkaline Phosphatase; D000118:Acetylglucosaminidase; D007931:Leucyl Aminopeptidase; D010130:p-Aminohippuric Acid