Search PubMedSearch

Biomedical subjects

E Ginter

Publications and source records attributed to E Ginter.

At least 37 records · Page 2Linked to original sources

Interactions between hepatic ascorbic acid, cytochrome P-450 and lipids in female guinea pigs with different ascorbic acid intake.

Changes in serum and liver lipids, hepatic ascorbic acid (AA) and cytochrome P-450 were investigated in female guinea pigs divided into three groups with different AA intake in drinking water (10, 100 and 1000 mg AA per liter) for 10 weeks. Serum and liver total cholesterol significantly decreased in guinea pigs receiving 100 and 1000 mg AA per liter of drinking water when compared with guinea pigs with suboptimal AA intake (10 mg/l). Similarly, serum triglycerides were decreased in the groups with higher AA intake. Liver AA concentration increased significantly in accordance with rising AA doses. High AA intake (1000 mg/l) for 10 weeks resulted in significant increase of both cytochromes P-450 and cytochrome b5 and total haeme content in liver microsomes when compared to guinea pigs with suboptimal AA intake. A significant positive correlation between hepatic AA concentration and cytochrome P-450 content was observed. A close negative correlation between liver total cholesterol and cytochrome P-450 content in hepatic microsomes was also seen. Long-term suboptimal AA intake may unfavourably alter the blood and liver lipid profile as well as the capacity of hepatic drug metabolizing enzymes in both male and female guinea pigs.

Animals

Selenium concentration in plasma and erythrocytes in a healthy Slovak population.

To obtain reference values for plasma and erythrocyte selenium concentrations blood specimens were collected from healthy adults from the Bratislava region. In 174 people, 20 to 60 years old, a plasma Se concentration of 56.2 +/- 8.5 micrograms/L and in 133 persons an erythrocyte Se level of 95.3 +/- 16.3 micrograms/kg were found (mean +/- SD). Selenium levels showed a normal distribution in plasma and erythrocytes. No differences were found according to sex or age. These results indicate that the Slovak population has a low Se status, with values for plasma Se being among the lowest in Europe.

Adult

[The role of antioxidants in the prevention of cardiovascular diseases].

The potential role of natural antioxidants (vitamin C--ascorbic acid, vitamin E--tocopherols, carotenoids and selenium) in the prevention of cardiovascular diseases is reviewed. It is probable that free oxygen radicals and oxidatively modified particles of low-density lipoproteins (LDL) participate in the development of atherosclerotic lesions. A great number of experimental, cross-sectional, retrospective and prospective epidemiological studies found a substantial increase of the risk of ischemic heart disease and stroke in individuals and populations with low intake of antioxidants from diet. Extremely high cardiovascular mortality in Slovakia and other postcommunist countries could be only partially explained by "classical" risk factors (hypertension, hypercholesterolemia and smoking). In the communist European countries there was a high consumption of spirits, cigarettes and salt, polluted environment and low consumption of the chief source of antioxidants--fruits. In these countries emphasis should be given to the prevention of antioxidant deficiencies by the increase of fruit and vegetable consumption, and to the decrease in salt, spirit, cigarettes and saturated fat consumption.

Antioxidants

Erythrocyte membrane fluidity and tissue lipid peroxides in female guinea-pigs on graded vitamin C intake.

The effect of low (1 mg/animal/day), medium (10 mg/animal/day) and high (100 mg/animal/day) intake of ascorbic acid on tissue lipid peroxidation (LPO) and the physical state of erythrocyte membranes was investigated in female guinea-pigs fed a vitamin E low diet. Animals were killed after 9-11 weeks and the blood, liver, lungs, kidneys and adrenals were analysed. The LPO was estimated by the determination of malondialdehyde with HPLC. The physical state of erythrocyte membranes was determined spectrofluorometrically and expressed as fluorescence polarization of membrane lipid specific probe 1,6-diphenyl-1,3,5-hexatriene. The LPO concentrations in the liver and adrenals of the group on a low vitamin C intake were significantly increased. A significant non-linear negative correlation between C vitamin levels and LPO concentrations was found in these tissues. The fluidity of erythrocyte membranes as a measure of their structural state was significantly lower in the group with a low intake of C vitamin. It is probable that the water-soluble antioxidants, such as vitamin C, act in the plasma as primary defense against oxidative stress if the radicals are formed initially in the aqueous phase of whole blood.

Adrenal Glands

Serum copper, zinc and copper/zinc ratio in males: influence of aging.

Apparently healthy free-living (non-hospitalized) men aged 8-89 years (n = 408) were studied to determine the effect of age on serum copper and zinc concentrations and the copper/zinc ratio. Mean values +/- S.D. for age, serum copper and zinc levels and the copper/zinc ratio were as follow: 41.9 +/- 22.9 years, 1.15 +/- 0.17 micrograms/ml, 0.93 +/- 0.14 micrograms/ml and 1.25 +/- 0.19, respectively. In the elderly subjects above 75 years, a marked increase in serum copper concentrations and the copper/zinc ratio as well as a decrease in serum zinc concentrations were observed. Serum copper concentrations and the copper/zinc ratio correlated positively with age (p < 0.0001).

Adolescent

[Determination of ascorbic acid in blood serum using high-performance liquid chromatography and its correlation with spectrophotometric (colorimetric) determination].

Insufficient supply of the populations of the Czech and Slovak Republics with vitamin C is connected with the occurrence of some diseases due to modern civilization. It is therefore necessary to obtain reliable data about the supply of the population with this most important antioxidant of blood plasma. In order to establish a simple, rapid and at the same time specific determination of vitamin C in serum, the present authors have introduced, on the basis of foreign data, the HPLC method of determination of ascorbic acid on reverse phases with UV-detection (245 nm), using 3.7 mM KH2PO4 (pH = 4) as the mobile phase. Very good separation of ascorbic acid from serum (Fig. 1) was obtained. The detection limit is 3.25 pmol of ascorbic acid. Parallelly with the chromatographic determinations, ascorbic acid was determined in 235 volunteers also by the spectrophotometric (colorimetric) method employing 2,4-dinitrophenylhydrazine. Both methods correlate very well (Fig. 2): correlation coefficient, r = 0.93, the level of probability p < 0.000001. The yield (Table 1) is 98.6% and 97.6% for HPLC, or 105.4% and 111.4% for the colorimetric method. The reproducibility of both methods gives coefficients of variation of 3.6% and 2.9%. The described HPLC method is sufficiently precise, specific and suitable for the determination of the levels of ascorbic acid in serum.

Adult

The influence of ascorbic acid on selected parameters of cell immunity in guinea pigs exposed to cadmium.

The study investigated the possibility of influencing immunotoxic effects of Cd through ascorbic acid. Guinea pigs with high and low intake of ascorbic acid were perorally exposed to cadmium chloride (1 mg Cd/animal/day). The daily vitamin C intake was 2 and 100 mg per animal, respectively. Phagocytic activity of polymorphonuclear leucocytes and monocytes as well as the percentage of active and total T lymphocytes in peripheral blood of animals were evaluated. Five- and 12-week experiments showed a mutual potentiation of negative effects of Cd on the immune system by suboptimal intake of ascorbic acid. Toxic effects of Cd on the immune system can be reduced by a sufficient intake of vitamin C.

Animals

Effect of the oyster fungus on glycaemia and cholesterolaemia in rats with insulin-dependent diabetes.

We have investigated the effect of a diet containing of 4% oyster fungus (Pleurotus ostreatus) and 0.1% cholesterol on glycaemia and hyperlipoproteinaemia in rats with insulin-dependent diabetes (streptozotocin 45 mg/kg). After two months, the rats with diabetes kept on the oyster fungus diet, had a significantly lower basal and postprandial glycaemia, the insulinaemia remained unchanged. The cholesterol concentration was decreased by more than 40%, the lipoprotein profile was upgraded by the decrease of the cholesterol in both the low density and very low density lipoproteins. The oyster fungus decreased the cholesterol accumulation in the liver and had no significant effects on the levels of serum and liver triacylglycerols.

Animals

Response of hepatic drug-metabolizing enzymes to immobilization stress in rats of various ages.

The effects of acute two-hour immobilization stress in hepatic microsomal drug-metabolizing enzyme activities, liver and blood serum zinc and copper levels, content of vitamin C in adrenals, were studied in rats of three age categories (4, 12, 24 months old). Immobilization stress resulted in marked reduction in the concentrations of vitamin C in adrenals of all age categories. In stressed animals, the activities of microsomal aniline hydroxylase, p-nitroanisol 0-demethylase, and the hepatic concentrations of microsomal protein were significantly increased in young 4-month-old rats, especially. In these rats increased levels of zinc in blood serum and copper in the liver, were seen. The levels of zinc and copper in older rats after immobilization stress were apparently unchanged. Age-dependent decrease in the activities of hepatic microsomal monooxygenases and adrenal vitamin C content in control rats were observed.

Adrenal Glands

Effect of the oyster fungus on glycaemia and cholesterolaemia in rats with insulin-dependent diabetes.

We have investigated the effect of a diet containing of 4% oyster fungus (Pleurotus ostreatus) and 0.1% cholesterol on glycaemia and hyperlipoproteinaemia in rats with insulin-dependent diabetes (streptozotocin 45 mg/kg). After two months, the rats with diabetes kept on the oyster fungus diet, had a significantly lower basal and postprandial glycaemia, the insulinaemia remained unchanged. The cholesterol concentration was decreased by more than 40%, the lipoprotein profile was upgraded by the decrease of the cholesterol in both the low density and very low density lipoproteins. The oyster fungus decreased the cholesterol accumulation in the liver and had no significant effects on the levels of serum and liver triacylglycerols.

Animal Nutritional Physiological Phenomena

Zinc and copper in the tissues and serum of cadmium intoxicated guinea-pigs: influence of vitamin C.

Cadmium in the dose of 1 mg/animal/day was administered to guinea-pigs in the form of CdCl2 dissolved in drinking water during short-term (5 weeks) and subchronic (12 weeks) experiments. Both the control and cadmium-treated groups were divided into two subgroups, according to low (2 mg/animal/day) and high (100 mg/animal/day) vitamin C intake. Subchronic cadmium treatment caused copper deficiency indicated by a dramatic decrease of copper concentration in the liver and serum and by its moderate decrease in the testes and brain. Cadmium significantly increased zinc concentrations in the kidneys during the whole experiment and decreased the level of zinc in the serum after subchronic cadmium treatment. In the control groups, the levels of zinc and copper in the serum were lowered after 5 weeks of high vitamin C doses. High doses of vitamin C in cadmium-treated guinea-pigs decreased the levels of copper in the testes, brain and serum. These observations suggest that cadmium intake in relatively high doses might potentiate the development of copper deficiency, and high doses of vitamin C aggravate, to a certain extent, copper depletion in some important organs and serum of guinea-pigs.

Administration, Oral

The effect of ascorbic acid on cadmium accumulation in guinea pig tissues.

Accumulation of cadmium in organs of guinea pigs after subchronic oral cadmium treatment (1 mg Cd/animal/24 h) was in the following order: kidneys > liver > heart > testes > brain. The preventive effects of high doses of ascorbic acid (AA) against cadmium deposition were more pronounced in the testes, heart and brain, and in the kidney only after short-term cadmium treatment. Ascorbic acid had no protective effect on cadmium accumulation in the liver.

Analysis of Variance

The influence of ascorbic acid on lipid peroxidation in guinea pigs intoxicated with cadmium.

Cadmium (as CdCl2) administered at a dose of 1 mg Cd/animal/day in drinking water to guinea pigs with a low intake of ascorbic acid (2 mg/animal/day) increased lipid peroxidation (LPO) in the kidney, liver and serum after 5 wk of treatment. A high intake of ascorbic acid (100 mg/animal/day) decreased LPO (determined from malondialdehyde levels) in the kidney, liver and serum of Cd-treated guinea pigs. Administration of Cd to guinea pigs with a low intake of ascorbic acid significantly increased LPO in the kidney at 5 wk, in comparison with controls given low levels of ascorbic acid but no Cd. However, at 12 wk, LPO in the kidney of Cd-treated guinea pigs was significantly lower than in the controls. These results indicate that the level of lipid peroxides in the kidney of guinea pigs with a low intake of ascorbic acid depends on the amount of accumulated cadmium.

Administration, Oral

Plasma lipids, lipoproteins and atherogenic index in men and women administered vitamin C.

The aim of the study was to establish whether it is possible, in a group of deliberately selected subjects with hyperlipidaemia, to modulate cholesterol levels by ascorbic acid administered at a dose of 500 mg/day. The authors assessed the levels of vitamin C, total and HDL cholesterol, triacylglycerols in the blood serum of 140 probands assigned to an 83-member experimental group, and to a 57-member control group. The experimental group was provided Celaskon effervescens Spofa at a dose of 500 mg/day/person. The experiment lasted for 18 months. Blood collections were made in the whole cohort at six-month intervals. Administration of L-ascorbic acid led to a highly significant decrease in the levels of total and LDL cholesterol. After 12 months of study, a highly significant decrease in atherogenic index and an increase in HDL cholesterol levels were found persisting until the end of the experiment.

Arteriosclerosis

[Plasma cholesterol levels and ischemic heart disease: new findings and new approaches].

The information explosion characteristic of recent years has presented a series of findings enabling a more effective prevention of ischemic heart disease by controlling low density lipoprotein (LDL) levels of cholesterol. The detection of LDL receptors has provided new information on the mechanisms regulating the level of plasma LDL. Data on competitive inhibitors of endogenous cholesterol synthesis have afforded new possibilities of pharmacological control of LDL levels. Studies of primary prevention of ischemic heart disease have yielded evidence showing that a 1% decrease of cholesterol level reduces coronary risk by 2%. A prospective study of the relationship between cholesterol levels and coronary mortality, absolutely unique as to its extent (368,000 middle-aged men followed up over a period of 6 years) has demonstrated that there is no borderline cholesterol level below which coronary risk would be absolutely excluded. Between total cholesterol level and coronary mortality there is a close, continual and graded relationship. In light of these findings, total cholesterol levels have been reclassified: desirable levels -5.2 x 10(-3) mol.l-1, borderline risk levels under 5.2-6.2 x 10(-3) mol.l-1, and high risk levels--above 6.2 x 10(-3) mol.l-1. In subjects with several risk factors (smoking, hypertension, familial occurrence of heart, heart disease, obesity, diabetes mellitus, HDL cholesterol below 0.9 x 10(-3) mol.l-1) the level of total cholesterol should be brought down below 4 x 10(-3) mol.l-1.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent

[A new concept of atherogenesis: the role of oxygen radicals].

The author discusses a new concept of atherogenesis which is based on older hypotheses (lipid infiltration hypothesis), theory of impaired endothelial barrier, role of immunological and thrombocytic factors) and supplements it by new findings on the role of oxygen radicals in the development of atherosclerosis. The atherogenity of native low density lipoproteins (LDL) is enhanced substantially by their post-secretory changes caused by the action of free oxygen radicals on unsaturated fatty acids in the outer layer of LDL particles. The development of lipid peroxides on the surface of LDL leads to a changed orientation of the metabolism of LDL particles: oxidized LDL are not bound to classical LDL receptors in the liver but to so-called scavenger receptors in monocytes and macrophages. Lipid accumulation in monocytes, not controlled by feedback mechanisms, leads to formation of foam cells which are the basis of atheromatous plaques. This process can be influenced by antioxidants which block the formation of lipid peroxides. The new concept is particularly important for the population of Czechoslovakia and other formerly totalitarian countries where deterioration of the environment occurred and concurrently also adverse dietary changes (high fat, sucrose and spirit intake, low vegetable and fruit consumption). It is probable that an increased intake of antioxidants (ascorbic acid, carotenes, tocopherols, bioflavonoids, selenium etc.) would, along with other corrective provisions, suppress the steep increase of cardiovascular diseases.

Arteriosclerosis