摘要:

We explored the effects of oral glycerol administration (20 g) alone or in combination with a mixed meal on postprandial lipids, free fatty acids, high-density lipoprotein cholesterol and retinyl palmitate. We also tested the meal alone as a control. The metabolic behavior of 13C-labelled glycerol, mainly its incorporation into triglycerides and glucose, was also investigated. The tests were performed on 13 healthy subjects aged 20-56 years (mean 32.1 ± 10.8). Glycerol administration alone induced a decrease in plasma free fatty acid levels. When glycerol was given with the meal, it was absorbed faster and postprandial triglyceride levels were higher compared to the meal alone (p < 0.05). An earlier and higher peak of retinyl palmitate was also observed when comparing the glycerol and mixed meal test to the mixed meal alone. No significant effect was observed on total, high-density and low-density lipoprotein cholesterol. These results suggest that the glycerol-induced increase in postprandial triglyceride levels is probably due to an increase in chylomicron synthesis and perhaps to the stimulation of intestinal glycerol kinase activity. 13C-labelled glycerol administration showed a more important glycerol incorporation in lipoproteins with a density range of < 1.006 during the test with glycerol alone as compared to the test with glycerol and a mixed meal, suggesting that the rate of glycerol incorporation into lipoproteins depends on the availability of other substrates

ISSN:0250-6807    

DOI:10.1159/000177846

出版商:S. Karger AG    

年代:1995

数据来源: Karger

摘要:

To estimate the effect of possible goitre prophylactic measures on the intake of iodine among population groups, simulation studies, based on the first Dutch National Food Consumption Survey, were carried out. Iodine intake figures and prevalence of low intakes were calculated after fictively iodizing either bread, a combination of industrial products, milk and dairy products (without cheese) or margarine and shortenings. In addition, the effect of iodizing both bread and cheese or bread + biscuits + rusks was calculated. The simulated iodization of different products increased mean calculated iodine intakes by up to 45% and gave a reduction of 60-90% in the prevalence of iodine intakes below 100 µg/day. The maximum acceptable intake of 1 mg iodine per day was never reached by any subject (average of 2 days). It is concluded that it is possible to increase substantially the mean iodine intake of the Dutch population and to decrease the prevalence of low iodine intakes without a clear risk of exceeding the maximum acceptable daily oral iodine intake

ISSN:0250-6807    

DOI:10.1159/000177847

出版商:S. Karger AG    

年代:1995

数据来源: Karger

摘要:

Freshly weaned 30-day-old male Wistar rats were fed a vitamin D-deficient diet adequate in calcium and phosphorus for 3 months. On the 120th day of age three different doses of vitamin D were injected intramuscularly into three groups of rats and maintained for another month with water and a normal diet ad libitum. One group was continued with a vitamin D-deficient diet up to the 150th day. One group of animals was killed by decapitation on the 120th day and testicular functions like sperm count in testis and epididymis, testicular glutamyl transpeptidase activity and Leydig cell count as well as body weight were noted. On the 150th day animals of all groups were killed and testicular function was studied. Body weight and testicular function decreased significantly on the 120th and 150th day of age in vitamin D-deficient rats as compared to age-matched normal control rats. Injection of lower doses of vitamin D on the 120th day of age improved testicular function after 1 month whereas administration of a high dose of vitamin D caused a deterioration of the testicular function. The result suggests that retardation of spermatogenesis due to disturbances in Sertoli and Leydig cell function in vitamin D deficiency is reversible and can be corrected by supplementing an optimal dose of vitamin D.

ISSN:0250-6807    

DOI:10.1159/000177848

出版商:S. Karger AG    

年代:1995

数据来源: Karger

摘要:

The inhibitory effect of probucol on ferrous-iron-induced microsomal lipid peroxidation was compared to that of α-tocopherol and butylated hydroxytoluene (BHT). Male Wistar rats were fed with diets containing 1 % probucol, 0.2% BHT or 0.1 % α-tocopherol for 30 days. There were no effects of dietary antioxidants on growth parameters, although liver weight was significantly higher in the BHT-fed rats. Probucol reduced serum levels of total and free cholesterol, while BHT feeding increased the concentrations of serum thiobarbituric-acid-reactive substances, HDL cholesterol and hepatic phospholipid. α-Tocopherol had no effect on these parameters. Incorporation of both, probucol and α-tocopherol, decreased the susceptibility of microsomes to lipid peroxidation in vitro, while BHT incorporation increased hepatic microsomal lipid peroxidation. These results suggest the possible usefulness of probucol for treatment of both hypercholesterolemia and elevated hepatic microsomal lipid peroxidation, while α-tocopherol decreases only an elevated lipid peroxidation. BHT works as a prooxi

ISSN:0250-6807    

DOI:10.1159/000177849

出版商:S. Karger AG    

年代:1995

数据来源: Karger

摘要:

The effects of dietary supplementation with acetic or propionic acid, given at a level of 3% of diets containing 2,500 or 2,750 kcal of metabolizable energy per kg, on levels of blood glucose, and on lipid, protein, and energy metabolisms were studied in female broiler chicks. Voluntary feed and energy intakes, as well as body weight gain, decreased significantly with the inclusion of the acids in either diet, in decreasing order of effect: propionate > acetate > nonsupplemented controls. The relative weight of the abdominal adipose tissue decreased significantly with the inclusion of either acid, but was unaffected by dietary energy level. In contrast, the weight of the liver was higher in birds fed the low-energy diet, but was unaffected by the anorectic agents. Inclusion of the acids increased the concentration of volatile fatty acids in the cecum and blood plasma. The rate of clearance of plasma propionate was greater than that of acetate. Anorectic agents and dietary energy density exhibited a synergistic effect on feed intake. These agents altered blood metabolites involved in lipid and energy metabolisms, but not in that of protein. Plasma metabolites and enzymes, particularly β-hydroxybutyrate and alkaline phosphatase, reflected the degree of feed restriction, supporting the hypothesis that the hypophagic effect of these acids is due to metabolic intervention

ISSN:0250-6807    

DOI:10.1159/000177850

出版商:S. Karger AG    

年代:1995

数据来源: Karger

摘要:

The ability to recover hepatic Δ6 desaturase (Δ6D) activity with linoleic acid as substrate was compared in adult and old rats. Male rats fed a diet deficient in α-linolenic acid were used either at 6 or 21 months. From these two ages onward, animals were fed a diet containing 10% fish oil for 3 months to reduce Δ6D activity. After this period, some of the animals were killed. The other animals were returned to the original diet deficient in α-linolenic acid. Fatty acid composition in liver and brain and hepatic Δ6D activity were analysed 3 and 7 days after the change in diet. When rats were fed the diet containing 10% fish oil, Δ6D activity was lower than in those fed the diet deficient in α-linolenic acid. The liver fatty acid composition was altered with disappearance of 22:5 n-6 and a decrease in 18:2 n-6,20:4 n-6 and 22:4 n-6 accompanied by an increase in 20:5 n-3,22:5 n-3 and 22:6 n-3. When rats were re-fed the original diet, Δ6D activity returned after 3 days to its initial level in the 9-month-old rats; in 24-month-old animals, recuperation was incomplete. The levels of 20:4 n-6 and 18:2 n-6 increased in the liver concurrently with a decrease in levels of 20:5 n-3, 22:5 n-3 and 22:6 n-3. In both age groups, the brain fatty acid profile remained unchanged 7 days after returning to the diet deficient in α-linol

ISSN:0250-6807    

DOI:10.1159/000177851

出版商:S. Karger AG    

年代:1995

数据来源: Karger

摘要:

The consumption of a low-fat diet is advocated as beneficial in the prevention of cardiovascular disease. Because of still existing controversy the hypothesis whether low fat intake < 30% of total calories can maintain optimal growth and supply the desirable quantity of micronutrients was tested in a cohort of 500 children in preschool age. The children, apparently in good health and without any special dietary regimen, were stratified according to fat intake in three groups: 40% of calories provided by fat. Our findings indicate that children with low fat intake were at a quite important risk of unsatisfactory intakes of fat-soluble vitamins, and also the nutritional density of consumed food was lower. The proportions of saturated (SFA), polyunsaturated and monounsaturated fatty acids were rather similar in all three groups, but cholesterol and SFA intakes decreased significantly in those with low fat intake. Serum cholesterol and triglyceride levels were however not significantly influenced.

ISSN:0250-6807    

DOI:10.1159/000177852

出版商:S. Karger AG    

年代:1995

数据来源: Karger

ISSN:0250-6807    

DOI:10.1159/000177853

出版商:S. Karger AG    

年代:1995

数据来源: Karger