Investigations on the mode of action of the fungus toxin orellanine on renal cell cultures.

The effects of the fungal nephrotoxin orellanine, of 2,2'-bipyridine and of 4,4'-bipyridine on monolayers of LLPCK1-cells were tested. It is shown by the E.C.50 on growing cells that orellanine is the most toxic of the tested bipyridyls. Orellanine causes disruption of confluent monolayers and decreases the activities of membrane bound alkaline phosphatase and of cytosolic lactate dehydrogenase. Also 3H-leucine and 3H-thymidine incorporation are reduced. In contrast to this, ATP- and NADPH-levels remain constant. The cell membrane is not affected. This indicates an intracellular mechanism of action.