摘要:

This study was carried out with three groups of weanling rats. One group was fed a high-protein (20%) diet, another group a low-protein (2.5%) diet, the third group a high-protein diet in restricted amounts. After 4 weeks of feeding, rats were injected simultaneously with L-[G-3H]-tryptophan and [carboxyl-14C]-nicotinic acid. The ratio of incorporation of [3H]-tryptophan to that of [14C]-nicotinic acid into liver NAD and NADP was found to be higher in protein-restricted rats. On the other hand, the ratio was found to be reduced in diet-restricted group of rats compared with ad libitum fed or low-protein diet fed groups. These results suggest that the efficiency of conversion of tryptophan to NAD is increased in protein deficiency, but reduced in the diet restriction. These observations are in line with our earlier findings on the changes in liver quinolinate phosphoribosyltransferase (EC 2.4.2.19) activity following feeding of low-protein or restricted diets. It is suggested that this technique of measuring the incorporation of two isotopes from the substrates labelled with two different isotopes can be conveniently used as a tool to measure the relative contribution of tryptophan and nicotinic acid to the synthesis of nicotinamide nucleotides.

ISSN:0250-6807    

DOI:10.1159/000176617

出版商:S. Karger AG    

年代:1983

数据来源: Karger

摘要:

In growing rats, an increase in ambiant temperature from 25 to 34 °C decreased the level of vitamin A by 54% in plasma and 17% in the liver. But the quantity of vitamin A available for the organism (quantity per gram body weight) remained unchanged. Various hypotheses have been formulated with a view to further research

ISSN:0250-6807    

DOI:10.1159/000176618

出版商:S. Karger AG    

年代:1983

数据来源: Karger

摘要:

Serum samples from girls from an elementary school in Western Sudan with grades 0,1 and II/IIIgoitre were examined for their thiocyanate, cysteine, thyroxine, TSH and T3 concentrations. The concentrations of thiocyanate in all girls was higher than that reported in the literature for Nigerians, but the concentrations of thiocyanate were nevertheless significantly elevated, and those of thyroxine significantly lowered in girls with grades I and II/IIIgoitre as compared with grade 0. There were no significant differences between any of the groups in the concentrations of cysteine or TSH and T3. The predominant staple food eaten in this area of Sudan is millet and evidence is produced that this contains a goitrogenic thionamide which could be a factor in causing the endemic goitre.

ISSN:0250-6807    

DOI:10.1159/000176619

出版商:S. Karger AG    

年代:1983

数据来源: Karger

摘要:

Metabolic studies were performed in 8 of 14 patients with severe anorexia nervosa (AN) before and after nutritional therapy. The decrease of lean body mass, as judged by the low values of the creatinine-height index (CHI), and the normal levels of visceral proteins demonstrate the marasmic pattern of undernutrition in AN. Low 24-hour urinary 3-methyl-histidine and urea levels agree with adaptation to malnutrition by decreasing in muscular breakdown. With enteral and oral feeding, weight gain was impressive and CHI reached normal values; 3-methylhistidine increased, reflecting enhancement of myofibrillar protein metabolism. By the end of refeeding, the levels of rapid-turnover proteins (prealbumin, retinol-binding protein) were higher than normal. Thus enteral feeding appears to be an efficient treatment of malnutrition in severe AN.

ISSN:0250-6807    

DOI:10.1159/000176620

出版商:S. Karger AG    

年代:1983

数据来源: Karger

摘要:

The thermogenic activity of ephedrine, ethinyloestradiol and triiodothyronine were compared by incorporating the drugs into the diets fed to groups of adult rats and mice. The animals used were normal lean mice, hypothalamic obese mice, dietary-induced obese mice and rats, and genetically obese mice and rats. Food intake and body weight were monitored throughout and oxygen consumption measurements were made. Finally, the animals were killed and their carcasses analysed. Generally, ethinyloestradiol reduced body weight by causing anorexia. Triiodothyronine increased oxygen consumption but also increased food intake such that in most cases body weight did not change; it killed the genetically obese animals, but reduced fat in the hypothalamic and dietary induced obese animals. The animals treated with ephedrine lost body weight and body fat without increasing food intake, and had elevated oxygen consumptions. This experiment not only demonstrated marked differences between the various laboratory animal models of obesity, but also that ephedrine is a potential slimming agent. It is relatively safe and has been used by us to obtain successful breeding using the genetically obese male animals which are normally sterile.

ISSN:0250-6807    

DOI:10.1159/000176621

出版商:S. Karger AG    

年代:1983

数据来源: Karger

摘要:

A nutritional and toxicological study has been made of rats, using the pair-feeding technique. The animals were fed a diet containing 5 % of NO-3 ion or 0.5 % of NO-2 ion (in the form of sodium salts). Under these conditions, a decrease was noted in the consumption of solid food which caused a net loss of weight. Besides, nitrates notably increase liquid intake and diuresis while nitrites induce a significant decrease in the protein retention coefficient.

ISSN:0250-6807    

DOI:10.1159/000176622

出版商:S. Karger AG    

年代:1983

数据来源: Karger

摘要:

Biotin deficiency was induced in germ-free rats using three experimental protocols. The results showed the important role of biotin during gestation and suckling. The earlier the deprivation, the earlier the deficiency and the severer the symptoms. In this vitamin deficiency, symptoms occurred that were not observed in the control rats, such as the formation of an intestinal volvulus in rats ingesting an L-isoleucine-supplemented diet. The main biochemical anomalies characteristic of propionic acidemia (ketoacidosis and increased urinary elimination of propionic acid) due to propionyl CoA carboxylase deficiency in man were not observed in the rats that were deprived of biotin for 200 days even after a dietary load of L-isoleucine. Only a small urinary excretion of propionyl-glycine and tiglylglycine was observed. We observed a drop in enzymatic propionyl CoA carboxylase activity in the liver that was proportional to the severity of the vitamin deficiency.

ISSN:0250-6807    

DOI:10.1159/000176623

出版商:S. Karger AG    

年代:1983

数据来源: Karger

摘要:

The characteristics of the digestive and hepatic metabolism of glucogenic and ketogenic substrates were studied in vivo in fed or starved rats. For this purpose, a procedure for blood flow measurements in the splanchnic area was developed, based on an indicator-dilution technique. Hepatic blood flow (HBF) was markedly reduced after 24 h starvation, mainly corresponding to the decrease of portal blood supply; however, HBF expressed per gram liver was almost unchanged. In overnight-fed rats, glucose absorption was limited and glucose was released by the liver, essentially after gluconeogenesis from C3 units: alanine was the main glucogenic substrate removed by the liver, then propionate and lactate, whereas only a slight release of pyruvate occurred. As large amounts of lactate were released by the digestive tract, there was a net production of lactate in the splanchnic area. In contrast, in starved rats, lactate became the main glucogenic substrate removed by the liver as its fractional extraction was raised from 7% (fed) to 58% (starved) whereas the contribution of alanine and propionate to gluconeogenesis was limited by their availability, their hepatic extraction being highly efficient in fed and in starved rats. The present results are consistent with the view that glucose turnover was practically halved during starvation and suggest that net glucose cycling via lactate was very low in fed rats but could correspond to about 40% of produced glucose in starved rats. Besides propionate, acetate and butyrate made a significant contribution to fuel supply for hepatic metabolism in fed rats, acetate availability for extrasplanchnic tissues remained relatively constant. FFA were extensively removed by the liver (50%) in starved rats and ketogenesis could account for 68 % of removed FFA. In spite of low concentrations in the artery, acetoacetate was released by the liver at a higher rate than 3-hydroxybutyrate. This process could correspond to a higher turnover rate for acetoacetate, nevertheless not evident in portal-drained viscera where net 3-hydroxybutyrate uptake was observed only.

ISSN:0250-6807    

DOI:10.1159/000176624

出版商:S. Karger AG    

年代:1983

数据来源: Karger

摘要:

Resting metabolic rate (RMR) and the thermic effect of feeding (TEF) two meals of differing energy densities were measured in 8 healthy elderly men aged 63–74 years. Similar measurements were made on 8 healthy young men aged 22–28 years. TEF was related to the meal size in both groups. Metabolic rate increased by 20.7 and 27.9% in the elderly group (EG) and 25.8 and 37.7% in the control group (CG) in response to the 2.0- and 4.0-MJ meals, respectively. Although the EG were fatter than the CG, they consumed a smaller daily food intake: we suggest that the decline in RMR and TEF as indicated by the study would explain this para

ISSN:0250-6807    

DOI:10.1159/000176625

出版商:S. Karger AG    

年代:1983

数据来源: Karger

摘要:

Calcium ions were infused into the external jugular vein of 2 groups of rachitic chicks. One group had been injected with 5 µg cholecalciferol (vitamin D3), while the other group remained vitamin D-deficient. After approximately 72 h the chickens were killed and intestinal mucosa homogenates were prepared for the measurement of calcium-binding protein (CaBP). The results indicate that CaBP is not biosynthesised in response to raising the extracellular calcium ion concentration, and only appears if the chickens had received cholecalciferol

ISSN:0250-6807    

DOI:10.1159/000176626

出版商:S. Karger AG    

年代:1983

数据来源: Karger