摘要:

21 -day-old female Norwegian Hooded rats were fed a riboflavin-deficient diet for 7 weeks. A control group consisted of individually weight-matched rats fed a complete diet. Reticulocytosis was induced by phlebotomy and heme synthesis measured in a reticulocyte-rich preparation in vitro. Concentrations of circulating iron and liver stores of ferritin iron and non-heme iron were measured. Riboflavin deficiency significantly impaired the process of accumulation and maintenance of hepatic iron stores but did not appear to influence the rate of heme synthesis in an in vitro system. A primary lesion in iron metabolism in young fiboflavin-deficient rats may be at the level of iron absorption so that assimilated iron is diverted to the erythroid marrow at the expense of repleting iron stores.

ISSN:0250-6807    

DOI:10.1159/000176980

出版商:S. Karger AG    

年代:1985

数据来源: Karger

摘要:

The concentrations of non-haem iron, ferritin and ferritin-iron were measured in the livers of 137 adults and children collected at necropsy. The concentrations of non-haem and ferritin iron were found to be 146.6 ± 95.2 µg/g and 61.6 ± 32.4 µg/g, respectively, in males and 108.0 ± 61.7 µg/g and 60.6 ± 26.4 µg/g, respectively, in females. The values for males in Singapore were lower than those reported in developed Western countries. No correlation was observed between storage iron and age, or ferritin concentration and age. Concentrations of non-haem iron and ferritin were similar for persons dying from accident and coronary heart disease. The non-haem iron concentration in Chinese (187.9 ± 101.0 µg/g) was significantly greater than that in Indians (103.1 ± 65.8 µg/g), while the ferritin concentration in Chinese (6.18 ± 2.37 mg/g) was significantly greater than either Malays (3.81 ± 1.8 mg/g) or Indians (3.52 ± 1.6 mg/g). A significant positive correlation was observed between the non-haem iron and ferritin and also ferritin-iron in Chinese males (r values of 0.678 and 0.598, respectively) and Indian males (r values of 0.576 and 0.612, respectively). However, the correlation between these indices was not significant in the case of Malay males. In premenopausal women the non-haem iron correlated well with ferritin (r = 0.737) and ferritin iron (r = 0.826) while the correlation was lacking in postme

ISSN:0250-6807    

DOI:10.1159/000176981

出版商:S. Karger AG    

年代:1985

数据来源: Karger

摘要:

Effect of soybean crude fiber on the concentrations of serum lipids and apolipoproteins in hyperlipemic subjects was examined. The concentrations of serum triglycerides, VLDL triglycerides and VLDL cholesterol were decreased significantly following the administration of soybean crude fiber for 2 months. Neither were significant changes found in total cholesterol, LDL cholesterol, HDL cholesterol, apo A-I, apo A-II, apo C-II and apo B levels, nor in body weight before and after the administration of soybean crude fiber.

ISSN:0250-6807    

DOI:10.1159/000176982

出版商:S. Karger AG    

年代:1985

数据来源: Karger

摘要:

Fat-supplemented diets enriched with linoleic acid by the addition of 12% w/w sunflower seed oil or proportionally reduced in linoleic acid by addition of 12% mutton fat were fed to rats for 18 months before the fatty acid composition of perirenal storage fat and myocardial membranes (phospholipids) was determined. Although the fatty acid composition of perirenal fat generally reflected that of the diet, there was an inverse relationship between the consumption of n-6 and the deposition of n-9 fatty acids. In addition, enhanced deposition of oleic acid (18:l, n-9) appears to be related to the dietary intake of stearic acid (18:0). In contrast, in myocardial membranes the n-3 polyunsaturated fatty acids are found to be increased when the intake of n-6 polyunsaturated fatty acids is reduced. This is particularly evident for docosahexaenoic acid (22:6, n-3) which is significantly increased in phosphatidylcholine, phosphatidylethanolamine, and diphosphatidylgycerol fractions of myocardial membranes, when the mutton fat diet was fed. After feeding the sunflower seed oil diet, the increased consumption of linoleic acid produced only small changes in the 18:2, n-6 content of cardiac phosphatidylcholine and phosphatidylethanolamine. These major classes of membrane phospholipids also showed only small increases in 20:4, n-6. In diphosphatidylglycerol, increased 18:2, n-6 also followed increased dietary intake, but this was not accompanied by increased 20:4, n-6. These changes in myocardial phospholipid fatty acid composition are similar to those observed after short-term feeding reported previously and confirm that changes in dietary n-6/n-3 fatty acid intake affect the fatty acid composition of both myocardial membranes and storage fat. These changes persist for the duration of the feeding period.

ISSN:0250-6807    

DOI:10.1159/000176983

出版商:S. Karger AG    

年代:1985

数据来源: Karger

摘要:

Serum 25-hydroxyvitamin D [25(OH)D], 24,25-dihydroxyvitamin D [24,25 (OH)2D] and 1,25-dihydroxyvitamin D [1,25(OH)2D] were studied in renal stone formers while on a diet containing 1,000 or 300 mg calcium per day. The patients were divided into four groups and identified as (a) normocalciuric (NSF), (b) absorptive hypercalciuric (AH), (c) renal hypercalciuric (RH) and (d) as having primary hyperparathyroidism (PHP). The results indicate that, on the 1,000-mg Ca diet, the mean 25(OH)D, 24,25(OH)2D and 1,25(OH)2D concentrations were within the normal range in all groups of patients. On the low-calcium diet, 25(OH)D concentrations decreased significantly in patients with AH and RH while 24,25(OH)2D concentrations were not affected by the low-calcium diet. 1,25(OH)2D concentrations increased significantly during dietary calcium restriction in all groups of patients. When the relationship obtained on each diet between the circulating 25(OH)D concentrations and the 25(OH)D/1,25(OH)2D concentration ratio was compared, it suggested that the increase in the 1,25(OH)2D concentrations during dietary calcium restriction may have been due to an increase in the capacity of the 25(OH)D-1α-hydroxylase, or to an increase in the circulating half-life of the hormone. These results indicate that renal stone formers are able to adapt themselves to dietary calcium restriction as shown by highly significant increases in the circulating 1,25(OH)2D concentrations while on a low-calcium diet. Moreover, the increase in the circulating 1,25(OH)2D concentrations did not happen at the expense of the 24,25(OH)2D production in any of the groups of patients studied

ISSN:0250-6807    

DOI:10.1159/000176984

出版商:S. Karger AG    

年代:1985

数据来源: Karger

摘要:

Rats of a normal selenium status were fed diets based on fish (rainbow trout) as the main protein source. A 4-week experiment with three dietary groups (low fish selenium, high fish selenium and selenite supplementation) was performed, and the selenium absorption, excretion and retention were recorded. Samples of blood serum, liver, kidneys, testes, hairs, spleen, lungs, heart, brain and skeletal muscle were collected for analysis of selenium. Glutathione peroxidase activity was measured in the blood serum. A selenium supplementation of approximately 1 mg/kg (high fish selenium and selenite group) yielded a selenium retention of only 7 % of the intake, while in the group with a dietary selenium concentration of approximately 0.1 mg/kg (low fish selenium group) the selenium retention was 50%, resulting in almost the same absolute selenium retention in all three groups. The liver and kidneys showed the highest accumulations of selenium, reflecting the participation of these organs in the excretion of surplus selenium. The highest relative uptake of selenium was recorded in the testes, which increased equally in all dietary groups. The selenium concentration in the other tissues investigated, as well as the glutathione peroxidase activity in the blood serum responded little to the selenium supplementations. These results showed that the selenium levels normally found in fish were sufficient to satisfy the need for this element in rats of a good selenium status, and that inorganic selenite was absorbed and excreted at a high rate already after 1 week.

ISSN:0250-6807    

DOI:10.1159/000176985

出版商:S. Karger AG    

年代:1985

数据来源: Karger

摘要:

Male rats were fed for 3–4 months (short-term) or 12–15 months (long-term) on a standard laboratory diet alone (control) or supplemented with sunflower seed oil (SSO, 12 % w/w) or sheep kidney fat (SKF, 12% w/w). Papillary muscles were electrically driven (1 Hz, 5 ms, supramaximal voltage) at 37 °C in Krebs-Henseleit solution, and contractions were measured isometrically. Both the positive inotropic responses to CA++ and the incidence of spontaneous tachyarrhythmias under catecholamine stress were increased by short-term SKF feeding and with age in control and SKF groups, whereas SSO prevented these changes. The results show a marked effect of age upon ventricular myocardial function in the rat, which appears to be accelerated by the consumption of animal (saturated) fat while polyunsaturated vegetable oil provides some degree of protection. It is suggested that changes in membrane lipid composition can alter the Ca++ handling characteristics of myocardial c

ISSN:0250-6807    

DOI:10.1159/000176986

出版商:S. Karger AG    

年代:1985

数据来源: Karger

摘要:

The effect of graded levels of thiamin on the metabolism of linamarin was investigated in rats. It was observed that on a diet deficient in thiamin, a large amount of linamarin was recovered unchanged in the urine, together with significantly more thiocyanate (SCN–) relative to the control. The least amount of thiocyanate (p < 0.05 relative to control) was found in animals receiving the highest amount (twice daily requirement) of thiamin in the diet; but the amount of unmetabolized linamarin was similar to the control. It is suggested that thiamin deficiency may be implicated in the aetiology of tropical ataxic neuropathy (TAN) through the thiocyanate overload in people eating large amounts of cassava and cassava derivatives which contain linamari

ISSN:0250-6807    

DOI:10.1159/000176987

出版商:S. Karger AG    

年代:1985

数据来源: Karger