EFFECT OF DIET AND BETA-NAPHTHOFLAVONE ON HEPATIC AND RENAL GLUTATHIONE-S-TRANSFERASE ISOENZYMES IN CARP (CYPRINUS-CARPIO)

Glutathione S-transferase (GST) isoenzymes were isolated from liver an d kidney of carp (Cyprinus carpio) by glutathione affinity chromatogra phy and chromatofocusing. Ten hepatic and eight renal catalytically ac tive isoenzymes were identified. GST subunits from purified isoenzymes were further separated by high-performance liquid chromatography (HPL C) and were used as standards for the experimental sample analysis. Ex perimental samples came from carp that were fed fish meal (standard di et) or soybean based diets for one year, injected or not with beta-nap hthoflavone (BNF; i.p. injection of 50 mg kg(-1)). HPLC did not allow us to identify precisely the GST isoenzyme pattern in experimental car p. However, GSTs could be pooled in three categories: homodimeric, het erodimeric and unidentified GST subunits. On this basis, the effect of diet and BNF on the GST isoenzyme pattern was investigated. The homod imer/heterodimer ratio was decreased in Liver of carp fed a standard d iet and in kidney of both dietary groups. BNF increased the total spec ific GST activity in liver and kidney. However, the GST isoenzyme patt ern was not modified in carp fed the standard diet while tissue specif ic modifications occured in carp fed the soybean diet. BNF decreased t he homodimer/heterodimer ratio in liver and increased it in kidney.