engleski

The effect of ochratoxin A on the activity of enzymes in the basal-lateral membranes of the proximal tubules of rat kidney

Ochratoxin A is a mycotoxin that is produced by storage moulds and could be found on variety of comodities. Maximal concentrations that were reported in food of plant and of animal origins were 27.5 mg/kg and 67 micrograms/kg, respectively. Numerous studies have shown that OA is a potent immunosupressive, carcinogenic, teratogenic and genotoxic agent. However, the most important toxic effects are found in the kidneys where and increased concentratio of OA are producing tubulo-interstitital nephropathy. LD50 for rats is 22-44 mg/kg b.w. The main goal of this study was to determine the effects of low doses of OA on the rat kidney. Daily dose of OA (120 micrograms/kg b.w.) was administrated to rats of Fisher stran during 10 and 35 days. Activities of Na, K-ATPase (the specific marker enzyme of basal-lateral membranes), gamma glutamyltransferase and alkaline phsophatase were measured in the basal-lateral membranes of kidney proximal tubule. The concentration of OA in kidney was found to be 32 ng/g tissue and 48 ng/g tissue after 10 and 35 days of experiment, respecitvely. Treatment lasting for 10 days produced a significant decrease in the activity of gamma-glutamyltransferase (reduction of 60 % in comparison to control value) and in the activity of alkaline phosphatase (reduction to 63 %). However, the activity of Na, K-ATPase was increased to 124 % after the 35 days of treatment.

ochratoxin A; rats; kidney; Na; K-ATPase; alkaline phosphatase; gamma-glutamyltransferase

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