Ultrastructural Observations of Colchicine-Effect on Ethionine-Induced Fat Accumulation in Rat Hepatocytes

Adult female Sprague-Dawley rats weighing 260-300g were starved overnight and injected i. p. with ethionine, 1 g/Kg, at the 11th hr of fasting, and a half of them was also injected i. p. with colchicine, 2.5 mg/Kg, twice at 3 and 6 hr after the single administration of ethionine. For the control fasting animals, the vehiclds (saline) were injected at the indicated times, respectively. All rats were sacrificed after having fasted a total of 20 hr, and the hepatocytes in periportal areas were examined with electron microscopy. The accumulation of larger biomembrane-bound lipid particles (diameter ; 0.2-0.4 prn) were greater in these hepatocytes of the rats injected doubly with ethionine and colchicine than the rats injected only with ethionine. Such hepatocytes of the former group had fewer intracytoplasmic lipid inclusions than the latter group, although the livers of both groups were harvested 9 hr after the ethionine injection. The control fasting rats treated with or without colchicine showed no distinct fatty livers. These observations indicate that colchicine inhibits the development of intracytoplasmic lipid inclusions within ethionine-injured livers of fasting female rats, and that this inhibition is accompained by a significant increase of larger biomembrane-bound lipid particles,