Effects of vitamin E on dolichol content of rats acutely treated with 1,2-dichloroethane

Previous investigations have demonstrated that 1,2-dichloroethane (DCE) poi soning affects dolichol (Dol) concentration in rat liver. Dol, a long-chain polyprenol, is considered an important membrane component: as dolichyl pho sphate, it is rate limiting for the synthesis of glycoprotein; as free or f atty acid, it is highly concentrated in the Golgi apparatus (GA) where it c an increase membrane fluidity and permeability, required glycoprotein matur ation and secretion. DCE biotransformation may stimulate pro-oxidant events through hepatocellular glutathione depletion. Since the molecules of Dol a re susceptible to oxidative degradation, the aim of this investigation is t o verify whether vitamin E (vit. E) supplementation in rats is able to prev ent Dol breakdown during acute DCE treatment. Before acute DCE administrati on (628 mg/kg body weight), a group of male Wistar rats were pretreated wit h vit. E (33 mg/kg body weight) for 3 days. High-performance liquid chromat ography analysis has shown that within 5-60 min after DCE administration, t he Dol concentration decreased in liver homogenate, cytosol, microsomes and GA. Particularly, 60 min after the treatment, Dol levels in the trans Golg i fraction were 71% lower than in controls. Rat pre-treatment with vit. E p revented the DCE-induced decrease in Dol concentrations of all liver fracti ons considered, in particular the reduction of total-Dol observed in the tr ans Golgi fraction 60 min after treatment was only 40%. These data suggest that hepatic metabolism of DCE is able to promote peroxidative attacks whic h lead to the degradation of Dol molecules. The pre-treatment of rats with vit. E results in a good, although not complete, prevention of total-Dol de pletion after DCE poisoning. (C) 2000 Published by Elsevier Science Ireland Ltd. All rights reserved.