Molecular aspects of human ochratoxicosis in Tunisia

Ochratoxin A (OTA) has been found in Tunisia since 1983 in foodstuffs and h uman blood primarily from rural areas. A nephropathy similar to Balkan Ende mic Nephropathy (BEN) has been found in Tunisian populations especially in nephropathic patients having OTA in blood due to chronic exposure by ingest ion of contaminated food. Some of them have shown several karyomegalic tubu lar cells in their renal biopsy. We designed investigations to produce in rat experimental nephropathy using OTA. These studies showed karyomegalic cells with alteration of renal tubu lar tissue combined with megacytosis. These observations suggested that the karyomegaly and megacytosis are induced by OTA in rats and could be also i n humans. In addition, abnormal mitosis are observed at the early stage of the pathology (30 days of treatment), suggesting that renal tubular cells c an regenerate if exposure to OTA is limited to a short period. After 90 day s of treatment the lesions became irreversible. The karyomegaly was worst. Apoptotic cells appeared, but abnormal mitosis were no longer observed.