Brevetoxin-3 (PbTx-3) on mouse liver slices: a histological study

Brevetoxin-3 (PbTx-3) is a marine toxin produced by the dinoflagellate Ptychodiscus brevis. Its effects on excitable tissues have been the main subject of studies, but little is known about how it affects non-excitable tissues. To study possible non-neural effects of PbTx-3 (78nM), its effects on hepatic cell structure in vitro were evaluated. PbTx-3 caused hypertrophy and increased vacuolation of hepatocytes, and an increase in basophilia in the perivenous area of the lobules. Ultrastructurally, it was evident that the vacuolation was related to swelling of the endoplasmic reticulum, changes that probably account for the increased basophilic reaction of the cells. The swelling in smooth endoplasmic reticulum, degranulation of rough endoplasmic reticulum, the deformities and lytic cristae in the mitochondria, and the presence of active lysosomes are evidence of the PbTx-3 effects upon liver cells. These responses are probably caused by the liver's detoxification role on the PbTx-3.