摘要:

Chicks with genetically elevated renal arginase activity were fed crystalline amino acid diets varying in ornithine concentration (0, 1 or 2%) to assess the potential for precursor regulation of polyamine synthesis. Renal arginase and renal and hepatic ornithine decarboxylase activities fell when ornithine was fed. Renal and hepatic ornithine concentrations rose while putrescine concentrations varied quadratically with ornithine feeding. Spermidine and spermine concentrations were not affected by diet. It was concluded that ornithine syntesized in vivo was a more potent stimulator of polyamine synthesis than ornithine of dietary origin.

ISSN:0250-6807    

DOI:10.1159/000177462

出版商:S. Karger AG    

年代:1988

数据来源: Karger

摘要:

The regulating process of cholesterol in the liver was studied in relation to its exogenous contribution in the rats fed high-fat (28%) high-cholesterol (1.2%) diets rich in saturated (S) fat (lard) or polyunsaturated (PU) fat (corn oil). Accordingly, the fate of 14C free cholesterol originating from high- or low-density lipoproteins (LDL) was examined in the biliary, hepatic and plasmatic lipids, as well as the activity of two key enzymes in the metabolism of lipoproteins: lipoprotein lipase (LPL) and lecithin cholesterol acyl transferase (LCAT). The LPL activity increased in the S diet, in comparison to the PU diet or to a low fat (6 %) control (C) diet and the LCAT activity increased but not significantly in the PU diet. In bile the secretion of 14C-cholesterol and 14C-bile salts originating from 14C-cholesterol-HDL increased in the S diet compared to the PU diet and a C diet [previous results]. S and PU diets increased to the same extent the hepatic storage of 14C-esterified cholesterol originating from LDL, compared to the C diet. This cholesterol would contribute to a greater extent to the hepatic synthesis of the lipoproteins destined for the plasma in the case of the S diet than that of PU diet. These results may be explained by the adaptation of hepatic acyl cholesterol acyl transferase and cholesterolesterase to both high-fat-diet enzymes acting simultaneously on the two free and esterfied cholesterol compartments. It resulted in an important redistribution of the cholesterol of these two compartments between plasma, bile and liver.

ISSN:0250-6807    

DOI:10.1159/000177464

出版商:S. Karger AG    

年代:1988

数据来源: Karger

摘要:

The effects of gastric inhibitory polypeptide (GIP) on glucose and lipid metabolism of isolated rat adiopocytes were investigated. In a dose-dependent manner, GIP stimulated 2-deoxy-glucose uptake increasing the glucose transport rate by up to 140% at a concentration of 10-7 mol/l. GIP also stimulated the conversion of 14C-glucose into extract-able lipids by up to 81 % at 10-7 mol/l. Insulin-stimulated 2-deoxy-glucose uptake and lipogenesis were additively enhanced by the presence of GIP. Insulin binding was slightly but not significantly increased by addition of GIP, mainly due to an increase in receptor affinity. GIP had a weak lipolytic activity, but lipolysis elicited by glucagon or isoproterenol was potently reduced. In conclusion, independent of its insulinotropic action, GIP showed a insulin-like activity on glucose metabolism and lipolysis in rat adipose tissue. The possible role of GIP for the development of obesity is discussed.

ISSN:0250-6807    

DOI:10.1159/000177467

出版商:S. Karger AG    

年代:1988

数据来源: Karger

摘要:

The effect of oral administration of vanadate on the transport and hydrolytic components of the glucose-6-phosphatase system in liver homogenates from streptozotocin-induced diabetic rats was examined. Blood glucose was normalized in diabetic rats receiving 0.8 mg/ml vanadate but a catabolic effect was observed on body and liver weight. Significant changes in the coupled reactions for glucose-6-phosphate transport by T1 and hydrolysis by the enzyme were noted. The dramatic elevation in the maximal velocity of glucose-6-phosphatase brought about by diabetes was suppressed by vanadate administration. As a result, the relationship between T1 and the enzyme returned to the normal range. It is concluded that the suppression of glucose-6-phosphate hydrolysis in diabetes may contribute to the normalizing effect of vanadate on blood glucose.

ISSN:0250-6807    

DOI:10.1159/000177469

出版商:S. Karger AG    

年代:1988

数据来源: Karger

摘要:

Variation factors of plasma retinol, carotenoids and vitamin E, and particularly sex and alcohol consumption, were studied on a sample of 271 males and females aged between 18 and 45 years. For analysis needs two subsamples were constituted: I (males and females with alcohol consumption ≤43 g/day) and II (males only). Sex and level of alcohol intake were two independent variation factors of plasma retinol and carotenoids. Associated with triglyceride and cholesterol for I and with triglyceride and ponderal index for II, they explained 40% of the total variance of plasma retinol. For carotenoids, the other associated independent variables were cholesterol, vitamin A and energy intake (r2 = 23% of explained variance). And for plasma vitamin E, neither sex nor alcohol consumption was a significant predictor of the model, the only variation factors being plasma lipids and age for I (r2 = 37%) and the same parameters associated with ponderal index for II (r2 = 55%

ISSN:0250-6807    

DOI:10.1159/000177472

出版商:S. Karger AG    

年代:1988

数据来源: Karger

摘要:

Rats treated with prolactin showed a rise in food consumption and an increased deposition of both lean tissue and fat. Rats pair-fed with untreated controls showed an increase in lean tissue, and a reduction in the activities of two key enzymes that control amino acid oxidation and urea synthesis in the liver. This adjustment in protein metabolism may regulate the amino acid supply in relation to the needs for milk protein synthesis during lactation.

ISSN:0250-6807    

DOI:10.1159/000177473

出版商:S. Karger AG    

年代:1988

数据来源: Karger

摘要:

Because the origin of atherosclerosis is often in childhood, an early identification of future adults at risk can contribute to the prevention of atherosclerosis. In a prospective study on nutrition and health, a cohort of 556 infants was followed from birth to 3 years. Among them, 116 were found at risk for hypercholesterolemia with a cholesterol level ≧ 200 mg/dl. Nine years later, these children at risk and their controls were invited to a follow-up examination of blood lipids, of nutritional status, by anthropometric measurements and personal and family history. From 32.7 to 48.7% of children at risk remained with a high cholesterol level (≧ 190 mg/dl) in comparison with 15% of controls. The nutritional profile was evidently different, especially the food frequency. The results strongly suggest that the early identification of children at risk and the screening of other family members, siblings and parents for hypercholesterolemia can serve for a sound intervention on nutritional hab

ISSN:0250-6807    

DOI:10.1159/000177474

出版商:S. Karger AG    

年代:1988

数据来源: Karger

摘要:

The consequences of hyperlipidic feeding on interscapular brown adipose tissue (IBAT) activity were examined in the cold-acclimated rat. Male Osborne-Mendel rats (7 weeks old) were exposed for 10 weeks at either 28 or 5 °C. The rats were fed a semipurified diet (normal fat (NL): 5 % lard; high fat (HL): 54% lard) for the last 9 weeks. IBAT weight was greater in HL than in NL rats. This increase was entirely due to accumulation of neutral lipids. Among different IBAT components (proteins, DNA, phospholipids) no variations were observed in HL 28 °C rats. HL diet did not modify lipoprotein lipase and cytochrome oxidase activities, but an increase in purine nucleotide binding (taken as an index of thermogenic activity) was observed in HL 28 °C rats. Cold acclimation led to comparable stimulation in NL and HL rats. The calorigenic effect of norepinephrine in vivo was not modified by HL diet. Study of arteriovenous differences showed that IBAT fatty acid and glycerol release by norepinephrine was slightly increased in HL 28 °C rats. No effect of HL diet was observed at 5 ° C. These results indicate that HL feeding leads to a moderate increase in the IBAT thermogenic capacity of Osborne-Mendel rats. HL diet does not modify the normal development of nonshivering thermogenesis when rats are kept in a cold environ

ISSN:0250-6807    

DOI:10.1159/000177475

出版商:S. Karger AG    

年代:1988

数据来源: Karger

摘要:

In 21 healthy children aged 6–11 years water balance studies were performed for 3 days at home. Water intake was assessed from dietary records based on the precise weighing method and water loss was calculated from repeated measurements of body weight and urine collection. Mean values ( ± SD) of all parameters of water balance are presented. Water intake from food and drinks without metabolic water of 43.0 ± 11.5 g/kg/day or 0.78 ± 0.17g/kcal (0.19 ± 0.04 g/kJ) resulted in a urine volume of 22.5 ± 7.7 g/kg/day and an osmolality of 24-hour urine samples of 756 ± 199 mosm/kg. From these data water intake seems to be low in these children. In school-aged children water intake from food and drinks of 1 ml/kcal (0.24 ml/kJ) as recommended for adults (Recommended dietary allowances, 1980) would seem adequate, theoretically resulting in a urine volume of 35 ± 14 g/kg/day and urine osmolality of 516 ± 182 mosm/kg based on the data in our

ISSN:0250-6807    

DOI:10.1159/000177483

出版商:S. Karger AG    

年代:1988

数据来源: Karger

摘要:

The effects of cold acclimation on cellularity, lipoprotein lipase (LPL) activity and lipolysis were studied in white adipose tissue of rats fed a high fat diet. Male Osborne-Mendel rats (7 weeks old) were exposed at either 28 or 5 °C for 10 weeks. The rats were fed a semipurified diet (normal fat (NL): 5% lard, high fat (HL): 54% lard) for the last 9 weeks. Caloric intake with NL and HL diets were comparable and cold exposure led to the same increase with both diets. At 28 °C, HL diet initiated both hypertrophy and hyperplasia; however, at 5 ° C only hyperplasia was observed. Total LPL activity showed high stimulation both in 28 and 5 °C HL rats. In vitro lipolytic stimulation by norepinephrine was lowered at 5 °C and abolished at 28 °C in HL-fed rats. HL diet resulted in enhanced lipid deposition without an increase in caloric intake. Even in cold-adapted Osborne-Mendel rats a relative obesity could be produced by a HL

ISSN:0250-6807    

DOI:10.1159/000177486

出版商:S. Karger AG    

年代:1988

数据来源: Karger