Metabolism of perorally administered xylitol in rat tissues.

Rats were given xylitol (X) or glucose (G) in drinking water for a period of 28-33 days of which the last 2 days also comprised intake of 14C(U)-X or -G. Samples of plasma, liver, kidneys, pancreas, duodenum and the parotid, submandibular and lacrimal glands were homogenized and separated into various fractions for radioactivity and chemical analyses. The X-fed animals had smaller lacrimal and submandibular glands than the G-fed siblings. The radioactivities of the plasma, liver and kidney trichloroacetic acid extracts of both sexes increased more in the X-groups. X increased the incorporation of the label into the total lipids of plasma, liver and duodenum in both sexes. In males, X increased the labeling of both the neutral lipids and phospholipids. In females, X increased plasma lysolecithin and decreased plasma lecithin. The organs of the X-fed females contained less ascorbic acid than those of the G-fed animals, except for plasma and the parotid glands. Several organs of the males also showed this phenomenon. X and G thus exerted selective effects on the exocrine glands. Although X entered easily the regular G metabolism and acted as a physiological carbon source, the incorporation of labeled X was, however, sex-dependent. The relationship between peroral xylitol and the metabolism of phospholipids and ascorbic acid should be especially considered in rats.