title: Ochratoxin A decreases the activity of phosphoenolpyruvate carboxykinase and its mRNA content in primary cultures of rat kidney proximal convoluted tubule cells.
abstract: The effect of ochratoxin A on the specific activities of phosphoenolpyruvate carboxykinase, gamma-glutamyl transpeptidase and phosphate-dependent glutaminase were investigated in primary cultures of rat kidney proximal convoluted tubule cells grown in a serum-free medium supplemented with growth factors. Addition of ochratoxin A (25-100 microM) to the medium caused reduction in the specific activities of phosphoenolpyruvate carboxykinase and gamma-glutamyl transpeptidase only. Addition of cAMP caused a four-fold increase in the concentration of phosphoenolpyruvate carboxykinase mRNA in tubule cells within 3 h. This cAMP-mediated increase in phosphoenolpyruvate carboxykinase mRNA content was abolished when ochratoxin A was added simultaneously.
authors.affiliation: Department of Biochemistry, Case Western Reserve University School of Medicine, Cleveland, OH 44106.
authors.forename: T J
authors.initials: TJ
authors.lastname: Thekkumkara
authors.forename: M S
authors.initials: MS
authors.lastname: Patel
mesh_terms: D000818:Animals; D015152:Blotting, Northern; D002478:Cells, Cultured; D000242:Cyclic AMP / Q000494:pharmacology; D005786:Gene Expression Regulation / Q000187:drug effects; D005972:Glutaminase / Q000378:metabolism; D007687:Kidney Tubules, Proximal / Q000166:cytology / Q000201:enzymology*; D009793:Ochratoxins / Q000494:pharmacology*; D010729:Phosphoenolpyruvate Carboxykinase (GTP) / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics; D051381:Rats; D011919:Rats, Inbred Strains; D013997:Time Factors; D005723:gamma-Glutamyltransferase / Q000378:metabolism
chemical_list: D009793:Ochratoxins; D012333:RNA, Messenger; C025589:ochratoxin A; D000242:Cyclic AMP; D005723:gamma-Glutamyltransferase; D005972:Glutaminase; D010729:Phosphoenolpyruvate Carboxykinase (GTP)