摘要:

Twelve antidepressant drugs, currently in clinical use, were screened for thermogenic properties on the basis of their ability to stimulate the activity of the sympathetic nervous system via an inhibitory effect on noradrenaline reuptake into the sympathetic neurons. Drug screening was carried out on mice made obese by hypothalamic lesioning using monosodium glutamate. Preliminary experiments, based on changes in body weight and food intake in response to increased doses of the drugs, indicate that most of the twelve antidepressants possess thermogenic potential. In particular, butriptyline, protriptyline and nortriptyline were most effective in causing marked losses in body weight without altering the food intake of the mice. The potent anti-obesity thermogenic properties of these three antidepressants were confirmed during a 10-week energy balance study involving measurements of energy expenditure over the entire period by the comparative carcass method, as well as by measurement of 24 h oxygen consumption. These studies indicate that the methodology employed in the preliminary screening is valid for identifying drugs with thermogenic potential, and demonstrate that many antidepressants currently in clinical use have marked thermogenic properties, and could therefore influence the nutritional status of patients under drug therapy.Introduction

ISSN:0250-6807    

DOI:10.1159/000177253

出版商:S. Karger AG    

年代:1987

数据来源: Karger

摘要:

Adult male Sprague-Dawley rats were subjected to food restriction so that they ate 65% of food ingested by control rats. While control rats had free access to food over the 24-hour period, food-restricted rats were provided with food daily at 10 a.m. The experimental period lasted for 34 days. On day 35, rats from both experimental groups were killed at 08.00, 11.00, 14.00, 24.00 and 02.00 h. Food restriction modified the circadian rhythms of ACTH and corticosterone. In addition, total circulating corticosterone throughout the day was higher in food-restricted than in control rats. In contrast, food restriction resulted in depressed secretion of thyroid-stimulating hormone and growth hormone. The results indicate that time of food availability entrained circadian corticosterone rhythm but not thyroid-stimulating hormone and growth hormone rhythms.

ISSN:0250-6807    

DOI:10.1159/000177254

出版商:S. Karger AG    

年代:1987

数据来源: Karger

摘要:

To a group of 8 healthy persons a slightly hypocaloric diet with protein (13% of energy), carbohydrates (46 % of energy) and fat (41 % of energy) was given as one meal or as five meals in a change-over trial. Each person was 2 weeks on each regimen. Under the conditions of slight undernutrition and neutral temperature the balances of nitrogen, carbon and energy were assessed in 7-day collection periods, and according to 48-hour measurements of gaseous exchange (carbon-nitrogen balance method) by the procedures of indirect calorimetry. Changes of body weight were statistically not significant. At isocaloric supply of metabolizable energy with exactly the same foods in different meal frequencies no differences were found in the retention of carbon and energy. Urinary nitrogen excretion was slightly greater with a single daily meal, indicating influences on protein metabolism. The protein-derived energy was compensated by a decrease in the fat oxidation. The heat production calculated by indirect calorimetry was not significantly different with either meal frequency. Water, sodium and potassium balances were not different. The plasma concentrations of cholesterol and uric acid were not influenced by meal frequency, glucose and triglycerides showed typical behaviour depending on the time interval to the last meal. The results demonstrate that the meal frequency did not influence the energy balance.

ISSN:0250-6807    

DOI:10.1159/000177255

出版商:S. Karger AG    

年代:1987

数据来源: Karger

摘要:

Resting energy expenditure (REE) was measured by indirect calorimetry during dieting (2.74–3.30 MJ/day) for up to 200 days in overweight patients undergoing continuous metabolic balance studies. The initial rapid reduction in REE in the first 2 weeks of dieting was related to the extent of the immediate nitrogen deficit that follows caloric restriction and was larger (p < 0.01) in men dieting de novo than either women (NS) or 4 patients of comparable lean body mass who had dieted prior to admission (NS). Because of their smaller metabolic energy deficit on our diets, the reduction in REE in women was small and not significant. In men, the slower long-term reduction in REE (p < 0.05) was related to a continuing loss of lean tissue with no changes in the REE/m2, REE/kg body weight and REE/mmol creatinine excreted with time. We have previously shown that total energy expenditure (estimated from the rate of fat loss as measured by the difference between body weight changes and weight changes in fluid and protein) does not change significantly during prolonged dieting. The fall in REE in parallel with lean body mass suggests that some increase in the energy expended in daily activities must have occurre

ISSN:0250-6807    

DOI:10.1159/000177256

出版商:S. Karger AG    

年代:1987

数据来源: Karger

摘要:

Food iron absorption data on 853 Indian women were compared to the haemoglobin concentrations, other iron-related measurements and the absorption of a reference dose of 3 mg iron given as ferrous ascorbate. The serum ferritin concentration was identified as the best predictor of the absorption of the reference dose (r = -0.54, p < 0.0001). These two measurements were then compared in terms of their relative ability to predict the absorption of iron from 10 individual meals. Results were comparable, with correlations for the pooled data of -0.50 (p < 0.0001) for the serum ferritin and 0.47 (p < 0.0001) for the reference dose. Since serum ferritin is a simple and non-invasive test, it may represent the more satisfactory way of standardising food iron absorption results to a common iron status in field studies. However, the value of such an approach is limited by the wide confidence limits of the relationship between food iron absorption and both the other measurements.

ISSN:0250-6807    

DOI:10.1159/000177257

出版商:S. Karger AG    

年代:1987

数据来源: Karger

摘要:

Postprandial thermogenesis of 8 healthy males of normal body weight and 17 healthy obese subjects with a body weight gain of more than 10 kg per year was measured continuously by means of a respiratory chamber over 10 h after test meals of 1 and 2 MJ protein (casein) and 2 MJ carbohydrate (hydrolized starch). The total thermic response to all test meals was reduced by about 50% in the obese subjects. The thermic response was related to body weight, energy intake, resting metabolic rate and weight loss during restricted energy intake. The necessity for a careful characterization of the obese subjects in studies of thermogenesis and of efficiency of energy utilization in obesity is pointed out. It is suggested that thermic response to food can be considered as a suitable indicator for the distinction between people of different metabolic efficiency.

ISSN:0250-6807    

DOI:10.1159/000177258

出版商:S. Karger AG    

年代:1987

数据来源: Karger

摘要:

In athletics, muscle and liver glycogen content is critical to endurance. This study compared the effectiveness of glucose and fructose feeding on restoring glycogen content after glycogen was decreased by exercise (90-min swim) or fasting (24 h). After 2 h of recovery from either exercise or fasting there was no measurable glycogen repletion in red vastus lateralis muscle in response to fructose. In contrast, glucose feeding induced a similar and significant carbohydrate storage after both depletion treatments (8.44 µmol·g-1 ·2 h-1). In the liver, following 2 h of recovery, the rates of glycogen storage were similar after either glucose or fructose ingestion, but fasting caused a greater rate of repletion (83 µmol·g-1 2 h-1) than exercise (50 µmol·g-1·2 h-1). After 4 h of recovery fructose-fed exercised animals had the highest glycogen concentration (165 µmol·g-1) followed by the glucose-fed exercised group (119 µmol·g-1). These values were 50 and 36%, respectively, of that measured in the normal-fed liver (327 µmol·g-1). In contrast, liver glycogen values in the fasted group decreased between the 2nd and 4th hour of recovery in response to both feeding regimens. From these results we conclude that fructose is a poor nutritional precursor for rapid glycogen restoration in muscle after exercise, but that both glucose and fructose promote rapid accumulation of glycogen

ISSN:0250-6807    

DOI:10.1159/000177259

出版商:S. Karger AG    

年代:1987

数据来源: Karger