The effect of increasing amounts of a cyclic oligosaccharide, beta-cyclodextrin (BCD), included in the diet on plasma cholesterol and triglycerides, was investigated in two animal models, namely in male genetically hypercholesterolemic Rico rats and in male Syrian hamsters. The distribution of bile acids in the gastrointestinal tract and in the feces of hamsters was also determined. In the Rico rats and hamsters, plasma cholesterol and triglycerides decreased linearly with increasing doses of BCD. In these two species, 20% BCD as compared to control diet lowered cholesterolemia (-35%) and triglyceridemia (-70%). In the hamster, the BCD diet caused a marked decrease in cholesterol and triglycerides in chylomicrons and very low density lipoprotein, and in high density lipoproteins cholesterol. Composition and amounts of bile acids were modified in the gastrointestinal tract of hamsters receiving 10% BCD as compared to the control group. The total bile acid content of the gallbladder of treated hamsters was fourfold higher than in the control group, and the bile contained a large amount of hydrophilic bile acids. This trend was also observed in the small intestine, in which percentages and total quantities of cholic plus deoxycholic acids (cholic pathway) were higher than those of chenodeoxycholic plus ursodeoxycholic plus lithocholic acids (chenodeoxycholic pathway). The bile acid contents of the cecum and colon of treated hamsters were 2.7-fold higher than those of control animals, but the bile acid composition was similar in the two groups of hamsters.(ABSTRACT TRUNCATED AT 250 WORDS)

We examined the effects of feeding conjugated linoleic acids (CLA) to adult male hamsters on several components of energy metabolism and body composition. Hamsters (n = 54) were assigned for 6-8 wk to one of three diets: 1) a standard diet (in percentage energy: lipids, 33, carbohydrates, 49, and proteins, 18); 2) to the standard diet augmented with the 9c,11t-isomer of CLA to 1.6% of energy (R group); or 3) the standard diet augmented with the 9c,11t-isomer and the 10t,12c-CLA isomer to 3.2 (1.6 + 1.6) % of energy (CLA mix group). (15)N uniformly labeled milk-protein was included in the diet to measure the incorporation of dietary protein into liver and muscle. Basal metabolic rate, thermogenic response to feeding and energy expenditure during spontaneous activity or during an exercise at approximately 60% of VO(2max) were measured. Carnitine palmitoyltransferase-I (CPT-I), leptin, insulin and triiodothyronine concentrations, as well as the in vivo overall adiposity changes were also determined. After 6 wk, the whole-body triglyceride content determined in vivo by NMR was significantly higher in the R group than in the control and CLA mix groups. The CLA mix group differed from the others in the lack of body triglyceride accumulation between d 21 and d 45 of the study, and the appearance of a slight insulin-resistance (homeostatic model assessment index, P < 0.05). Paradoxically, the lack of effect on whole-body lipid oxidation was associated with a greater CPT-I-specific activity in tissues of both CLA-fed groups (P < 0.05). No other major effects of CLA feeding were detected. In conclusion, CLA supplementation in hamsters did not affect adipose weight or the components of energy expenditure despite a theoretically higher capacity of red muscle to oxidize lipids. Only a CLA mixture prevented whole-body triglyceride accumulation over time.

No abstract

No abstract