Deformation of isolated rat hepatocytes by a peptide hepatotoxin from the blue-green alga microcystis aeruginosa

Abstract

The effect of the peptide hepatotoxin from the bloom-forming blue-green alga Microcystis aeruginosa was investigated on isolated rat hepatocytes. When toxin was added to hepatocyte suspensions it produced deformation of the cells, as shown by scanning electron microscopy. This was apparent within 5 min of addition of toxin to the cells and the response was dose dependent: 30 ng of toxin was sufficient to cause deformation in 58 +/- 9% of 1.4 x 10(6) hepatocytes/ml of incubation. The deformation did not lead to cell death as measured by Trypan blue uptake within 120 min. Deoxycholate, cholate bromosulphophthalein, and rifampicin were found to prevent the deformation of hepatocytes by Microcystis aeruginosa toxin in a dose dependent manner, analogous to the effect of these agents on the response of hepatocytes to added phalloidin. This suggests that Microcystis aeruginosa toxin is transported into hepatocytes in the same way as phalloidin; namely sharing a transport system for bile acids on the hepatocyte plasma membrane.