Subcellular distribution of tetrodotoxin in puffer fish liver

The liver homogenate of puffer fish was fractionated into blood cell, nucle ar, mitochondrial, microsomal and cytosol fractions by the differential cen trifugation method. All the five fractions were toxic to mice, although the toxin amount was significantly high in the cytosol fraction. Analyses by H PLC and LC-FABMS demonstrated that tetrodotoxin is the major toxic principl e in each fraction. These results reveal that tetrodotoxin is widely distri buted in organelles in liver cells, though predominantly in the cytosol fra ction. (C) 1999 Elsevier Science Ltd. All rights reserved.