Effect of dietary modification on the uptake of glucose, fatty acids, and alcohols in diabetic rats

Abstract

Nutrient uptake (Jd) is enhanced in diabetes mellitus (DM) in the rat; these studies were undertaken to determine the effect of 2 wk dietary modification on the Jd of fatty acids, fatty alcohols, and glucose. In control (C) rats, fatty acid Jd was lowest with the low essential fatty acid diet, but the incremental change in free energy (∫ΔFw➙ℓ) was not affected by the other diets; in DM ∫ΔFw➙ℓ was lower with the low cholesterol or high carbohydrate diets, and higher with the high cholesterol diet. The effective resistance of the intestinal unstirred layer was assessed from the Jd of lauryl alcohol. In C intestinal unstirred layer was lowest in the high carbohydrate group and highest in the low cholesterol group; intestinal unstirred layer was less in DM than in C only in the rats fed the low cholesterol diet. In C, varying the protein content of the diet was associated with a rise in the value of the maximal transport rate and the Michaelis constant, but a decline in the passive permeability coefficient for glucose. Glucose Jd was increased in DM rats fed a high carbohydrate or a high cholesterol diet; the values of the Kms were similar in DM and C, but the maximal transport rates were higher in the DM than in the C and these values were influenced by dietary modifications. Thus short-term dietary modification influences intestinal unstirred layer, ∫ΔFw➙ℓ, and the kinetic constants for Jd of glucose in control and diabetic rats.