Nutrition and metabolism最新文献

The metabolic rate of obese women and control group was established by indirect calorimetry. Each subject in resting state and during ergometer cycling test was examined three times a day, before meals. The resting metabolic rate of both groups increased during the day. During exercise the energy expenditure of obese subjects was significantly higher than that of the control group. The presented results show that in obese subjects the highest exercise energy expenditure appeared in the evening and in the afternoon.

In three series of experiments hypercholesterolemia was induced in male Sprague-Dawley rats by a 3% cholesterol-enriched diet. The development of hypercholesterolemia was considerably retarded when 20% Scenedesmus powder was incorporated in the diet. In animals fed with standard diet and cholesterol for 6-8 weeks, the average concentration of blood plasma cholesterol increased from 2.0 to 3.6 mmol/l. In contrast, the final concentration reached only 2.4-2.8 mmol/l in animals receiving the cholesterol diet with algae. The plasma cholesterol level in animals receiving only an algal diet did not appear to be influenced. The mean value at the beginning of the test was 2.0 and 2.2 mmol/l at the end. The level of plasma triglyceride in animals fed on algae with and without the addition of cholesterol was lower than that of the controls. The algae-enriched diet prevented an excessive deposition of cholesterol in the liver. The increase in weight of the livers of rats receiving the cholesterol-enriched standard diet and the cholesterol-enriched algal diet were 2.0 and 0.8 g, respectively. The cholesterol content of the livers increased to 600 and 180 mg, respectively.

The elimination of ethanol is known to be accelerated by fructose. Studies of continuous infusions of both ethanol and fructose as the basis for quantitative calculations are not available. In healthy volunteers fructose infusions were given for several hours during and immediately after the end of ethanol infusions. Both increase and elimination of ethanol in blood were effected to the same extent by fructose when compared to control experiments. Average increases in the elimination rates of ethanol were up to 80%; however, each subject displayed individual variations.

The effects of oxythioquinox (200 mg/kg fresh food for 30 days) on the growth, feeding, body composition and weight of various organs were studied in rats receiving isocaloric diets containing varying amounts of alimentary lipid (3, 18, 35 and 49%). With the exception of the liver, the kidneys and the ratio of ingested protein/gain in body proteins, which increased, all the investigated parameters showed a significant decrease under the effect of oxythioquinox. Since the various diets were isocaloric and the ratio total calories/proteins (g) was constant, no effects directly due to the level of lipid were seen on the parameters studied except the weight of the caecum which decreased. The interactions observed mirror an antagonism between the effects of the lipids and those of oxythioquinox.

Rachitic chicks were injected with different dose-levels of cholecalciferol and several cholecalciferol-related substances, i.e., dihydrotachysterol 3, ergocalciferol, 5,6-transcholecalciferol and 25-hydroxycholecalciferol. The response to treatment was assayed by the amount of cholecalciferol-dependent calcium-binding protein produced in the mucosa of the small intestine. The biological activity of these substances in the healing of rickets in the rat was also estimated except for ergocalciferol. The relative potencies in stimulating calcium-binding protein production were: 25-hydroxycholecalciferol > cholecalciferol > 5,6-trans-cholecalciferol > ergocalciferol > dihydrotachysterol 3.

A survey is given of the effects of a linoleic-acid-rich diet on arterial thrombosis, blood platelet function and blood pressure in rats and man, and on coronary flow rate and heart muscle function of isolated rat hearts. Dietary linoleic acid decreases arterial thrombosis tendency in a dose-dependent manner in rats, as measured by the aorta loop technique. In a group of patients, a linoleic-acid-rich diet improved blood platelet aggregation measured with the filtragometer as compared with a similar group which was given a linoleic-acid-poor diet. The patients who received a high linoleic acid diet showed a lower cardiovascular death rate than the low linoleic acid group. Salt-induced hypertension in rats can be prevented and cured by a high linoleic acid diet. In man, the results of a few experiments show a decreasing tendency of blood pressure during a diet enriched with linoleic acid. In the isolated hearts of rats fed a diet high in linoleic acid, coronary flow and heart muscle function both increase as compared to control groups fed lard or hardened coconut oil. The observed effects are discussed against the background of recent findings in the field of prostaglandin research.

Plasma lipoprotein abnormalities in maturity onset diabetes (MOD) reflect both enhanced production and impaired removal of triglyceride-rich lipoproteins. Hyperglycemia and hyperinsulinemia lead to overproduction of very-low density lipoproteins by the liver. Fat tolerance is reduced in MOD patients: this might be due to low lipoprotein lipase activity (LLA) and/or to low incorporation of LLA-released fatty acids into adipose tissue glyceride. This finding of abnormal low-density lipoprotein composition, with relative enrichment in triglyceride, suggests remnant particle accumulation.

Three groups, each of 9 adult male monkeys were maintained for about 18 months on diets containing mustard oil, either 5 or 10%; or 10% peanut oil, respectively. Histological examination of hearts of monkeys fed either 5 or 10% mustard oil diets did not reveal any abnormality attributable to mustard oil intake, such as vacuolation and fibrosis of myocardium. However, the oxygen consumption, RCR and ADP/O ratio, were significantly lower in the mitochondria isolated from monkeys receiving 10% mustard oil than those isolated from 10% peanut oil receiving monkeys, in the left ventricle but not in the right ventricle. Moreover, the oxygen consumption in the homogenates of left ventricles of monkeys receiving mustard oil, either 5 or 10%, was significantly lower as compared to that in 10% peanut oil controls. These data indicate that ingestion of mustard oil is associated with decreased oxidative capacity of heart mitochondria. They also suggest that the homogenates of the hearts of monkeys receiving mustard oil may contain a factor which further inhibits mitochondria oxidation.

In order to study the effects of a zinc-supplemented dietary rapeseed protein concentrate on the contents of zinc and some other minerals in plasma, liver and bone tissue as well as on the levels of tocopherol, lipoproteins and lipids in plasma and total lipid contents of livers, groups of young female rats were fed for 4-week periods on semi-purified diets containing either rapeseed protein or casein as the sole source of protein at a 20% protein level. Despite normal levels of tissue zinc and plasma proteins, rats on diets and tocopherol in comparison to the casein-fed rats. Rats on rapeseed diet also seemed to have an increased lipid content of the liver possibly indicating a reduced hepatic synthesis or secretion of lipoproteins. In addition the livers of rats fed on rapeseed protein diet showed a reduced iron content.