Effect of peroral xylitol on the concentration levels of lipids and electrolytes in rat tissues

Abstract

The effect of glucose (G) and xylitol (X) feeding on the fat and electrolyte metabolism was studied with 24 adult male rats divided into three groups of 8 for a 30-day experiment. One group was fed the stock diet supplemented with X (3000 mg/kg body wt./day); the second group the same diet supplemented with G (3000 mg/kg body wt./day), and the third the stock diet without added carbohydrates. During the last 24-hr period of the feeding schedule the animals were given 14C(U)-labeled G or X. Samples of serum, liver, kidneys, pancreas, spleen, duodenum wall, parotid glands, and the entire submandibular and lacrimal glands were analyzed for neutral lipids, phospholipids, Na, K, Mg, Ca, Fe, Cl − and inorganic phosphorus. The X-fed animals showed smaller weight gains and their lacrimal and submandibular glands were significantly smaller than in other feeding groups. The weights of kidneys, however, did not differ significantly. At least in the case of submandibular glands, the reduced gland weights were associated with decreased levels of tissue K, Ca, Mg, inorganic phosphorus and Cl −. Several organs of the G-fed animals displayed reduced Na contents. X-fed rats showed elevated concentrations of Fe in livers, kidneys and spleen, increased labeling of serum neutral lipids, and increased concentrations of triglycerides (TG) and free fatty acids (FFA) in lacrimal and submandibular glands. The G-fed animals showed decreased concentrations of serum lysolecithin, but elevated levels of TG in serum and the lacrimal and submandibular glands. X feeding increased serum lysolecithin compared to G feeding. These results suggest that physiological, peroral X administration increases the rate of lipolysis, facilitates the absorption of iron and exerts specific effects on exocrine gland function in rats. Most findings in the X group were significant only when compared to the G group. Minor differences existed when X-fed rats were compared to control rats. Since high carbohydrate diets usually result in reduced plasma FFA and increased plasma TG, the higher FFA and lower TG in the X-fed rats compared to the G-fed group, therefore, represented a lack of high G effects.