摘要:

The influence of an apple-supplemented diet on the distribution of cholesterol among the lipoproteins in plasma was studied using a special animal model: FEC hamsters which spontaneously develop hypercholesterolemia with aging when fed a commercial balanced diet. This metabolic disorder did not occur in animals freely consuming apples in addition to the standard diet. This combined diet essentially decreased the cholesterol content in the VLDL and LDL, the apo B-rich lipoproteins in plasma.

ISSN:0250-6807    

DOI:10.1159/000177242

出版商:S. Karger AG    

年代:1987

数据来源: Karger

摘要:

Plasma-, erythrocyte- and liver Se-dependent glutathione peroxidase (GPx) activity, ascorbic acid (AA) concentration, and erythrocyte and liver Se levels were analyzed in groups of guinea pigs fed a Torula yeast-based semipurified diet supplemented with either 0 (-AA), 200 (+AA), or 400 (++AA) mg of AA/kg of diet and either 0.05 (+Se) or 0.2 (++Se) ppm of Se for 24 days. Plasma, erythrocyte, and liver AA concentration were directly related to the levels of AA fed. There were 21.2 ± 2.7% and 51.2 ± 4.5% (p < 0.0001) increases in erythrocyte and liver Se, respectively, in ++Se guinea pigs compared to +Se guinea pigs. Dietary AA had no effect on erythrocyte or liver Se levels. Plasma, erythrocyte, and liver GPx specific activities were significantly (p < 0.001) increased in ++Se guinea pigs compared to +Se guinea pigs. In addition, liver, plasma, and erythrocyte GPx activities were directly related to the level of AA fed. These data indicate that dietary AA has no influence on tissue levels of Se but increases plasma, liver, and erythrocyte GPx activities in the guinea pi

ISSN:0250-6807    

DOI:10.1159/000177243

出版商:S. Karger AG    

年代:1987

数据来源: Karger

摘要:

Weanling male Hartley guinea pigs were fed for 6 weeks on a regular chow supplemented with 5 % polyunsaturated fats (safflower, linseed, or evening primrose oil) or 5 % saturated fats (hydrogenated coconut oil) with or without the addition of 1 % cholesterol to the diet. Cholesterol feeding resulted in slower growth, hyperlipidemia, and a fatty liver. Cholesterol contents (predominantly in the form of cholesteryl esters) in plasma and liver were increased, but the increase of plasma cholesterol was significantly reduced when unsaturated fats in place of saturated fat were added to the diet. The essential fatty acid contents in plasma and liver lipids were modulated by the dietary fats and by the cholesterol feeding. The latter reduced the proportions of 20:4 (n-6), but increased or had no effect on the levels of 18:2 (n-6). These results led to a reduced ratio of 20:4 (n-6)/18:2 (n-6), suggesting that cholesterol feeding may impair the desaturase activities.

ISSN:0250-6807    

DOI:10.1159/000177244

出版商:S. Karger AG    

年代:1987

数据来源: Karger

摘要:

Generally, protein energy malnutrition is accompanied with vitamin A deficiency. The present study was undertaken to evaluate the importance of the quality and the quantity of dietary proteins on the in vitro secretion and uptake of vitamin A in growing rats. The results show that the in vitro release of radioactive vitamin A was greater in rats fed Bengal gram diets as compared to those fed casein diets. However, this relationship between the two groups of rats was reversed for the in vitro uptake of radioactive vitamin A from plasma by various extrahepatic tissues. Thus the vitamin A status of the animal is profoundly influenced by the quality and the quantity of dietary proteins.

ISSN:0250-6807    

DOI:10.1159/000177245

出版商:S. Karger AG    

年代:1987

数据来源: Karger

摘要:

The ultrastructure of skeletal muscle and activity of some enzymes of energy metabolism were studied to assess the effect of a deficiency of dietary energy and subsequent nutritional rehabilitation in 24 young, growing, healthy rhesus monkeys. Electron microscopy of muscles on energy-deficient animals showed thinning of myofibrils with widening of interfibrillar space and enlargement and accumulation of mitochondria at subsarcolemmal level. There was an apparent significant reduction in the fiber size. Muscle samples from each animal were analyzed for enzymes representative of glycolysis (phosphofructokinase [PFK] and lactate dehydrogenase [LDH], citric-acid cycle (isocitric dehydrogenase [ICDH] and citrate synthase [CS] and regeneration of ATP (creatine kinase [CK]. PFK and LDH activities were significantly augmented in energy-deficient animals. The increase in LDH activity resulted from a large increase in MU (skeletal muscle) LDH subunit. The activities of CS and ICDH were reduced. No alteration of CK in muscle and serum was observed. The morphological structure and enzyme activities returned to normal after nutritional rehabilitation.

ISSN:0250-6807    

DOI:10.1159/000177246

出版商:S. Karger AG    

年代:1987

数据来源: Karger

摘要:

Variations in free sulphur amino acid content in some rat tissues have been measured during pregnancy and lactation. As a general trend, sulphur amino acids tend to accumulate in tissues in late pregnancy. This accumulation is quantitatively more important in the liver and striated muscle than in the skin and the kidneys. Among sulphur amino acids, taurine shows the most marked changes, with a maximum accumulation in the liver and striated muscle on day 19 of pregnancy. After delivery, the levels of amino acids in the tissue pools show a tendency to drop, especially in liver and striated muscle. As expected, taurine shows the most marked decrease, returning to normal values in muscle but decreasing to depletion in the liver on day 20 after delivery. These results can be interpreted as follows: during pregnancy, increased food intake is sufficient to accommodate the metabolic needs of the mother, but during lactation, the requirements of milk synthesis promote the release of these amino acids from the tissues.

ISSN:0250-6807    

DOI:10.1159/000177247

出版商:S. Karger AG    

年代:1987

数据来源: Karger

摘要:

Duodenums from freshly killed stock colony rats were incubated in Krebs buffer containing carrier-free 65ZnCl2 for periods of time between 5 and 60 s. Mucosa cytosol was separated and fractionated by gel filtration on Sephadex G-75.65Zn was present in two main bands of protein with molecular weights of about 45,000 and 6,500, but the ratio between them rose progressively with time of exposure to the isotope. Addition of metabolic inhibitors greatly lowered the 45,000/6,500 ratio for 65Zn. It is concluded that when zinc enters the mucosal cytoplasm during absorption, it rapidly binds to the 6,500 protein in a passive way and is then transferred to the protein of molecular weight 45,000 by an active process.

ISSN:0250-6807    

DOI:10.1159/000177248

出版商:S. Karger AG    

年代:1987

数据来源: Karger

摘要:

Cholesterol 7α-hydroxylase activity was determined in parallel with the rate of cholesterogenesis from acetate and mevalonate in the liver of hamsters fed diets enriched with pectins (5%) and/or cholesterol (0.1 %). Cholesterol feeding reduced the rate of incorporation of the precursors into cholesterol. Moreover, the radioactivity derived from mevalonate was found mainly in the esterified form of the newly synthesized molecules. In parallel, cholesterol 7α-hydroxylation decreased by 50%. Pectins did not greatly affect hepatic cholesterogenesis or 7α-hydroxycholesterol formation. In contrast, the fibers prevented to a large extent the metabolic alterations resulting from cholesterol feeding. Cholesterogenesis from mevalonate remained active; ester formation declined and the activity of cholesterol 7α-hydroxylase persisted. Pectins could maintain the activity of this enzyme through multiple mechanisms, one of them being the channeling of substrate into the specific compartment of cholesterol which is destined to form bile ac

ISSN:0250-6807    

DOI:10.1159/000177249

出版商:S. Karger AG    

年代:1987

数据来源: Karger