RESUMEN
The lack of a suitable animal model for Alzheimer research continues to be an impediment to the elucidation of the pathogenesis of the histological features of this condition, including PHF. Chronic ethanol intoxication induces the formation of PHF in young rats. Abnormalities in number and subcellular distribution of nematosomes in DRG of rats subject to chronic ethanol feeding has been noted by us. We present evidence that a vitamin A deficient diet promotes the formation of PHF and nematosomes in DRG of rats chronically intoxicated with ethanol. Three groups of young male Wistar BR rats were implanted with a gastrostomy cannula and infused with the following liquid diet: first group received 30% of total calories as corn oil, 32% ethanol, 25% protein with the balance as dextrose; 5% lard was substituted for the corn oil in the second group; the third group received 25% corn oil and was maintained in a vitamin A deficient state. Control animals were pair-fed the diet and isocaloric in dextrose with the experimental animals' alcohol intake. Animals were sacrificed at approximately 150 days and DRG were fixed in situ with a solution containing 2% paraformaldehyde and 2% glutaraldehyde. The increased number of nematosomes in all ethanol treated rats was prominent and more so in animals with a vitamin A deficient diet. A large amount of lipofuscin was usually associated with these thread-like structures which were of several types. Nematosomes commonly enclosed neurofibrillary tangles of PHF in animals treated with the ethanol-vitamin A deficient diet. PHF were rarely observed in other animals.(ABSTRACT TRUNCATED AT 250 WORDS)