The influence of alpha-tocopherol supplementation on plasma concentration of this vitamin and insulin in sedentary or physically trained rats.

Male young growing rats of Wistar strain (n = 54) were fed a vitamin E deficient diet for 3 days of adaptation period and then 10 days of experimental period. After adaptation half of the rats ran, once per a day, on a treadmill with a rate of 2.0 m/s for 15 minutes for the following 10 days. Animals were given orally 0, 0.5, 1.0 or 4.0 mg/d/rat of alpha-tocopherol. The aim of the study was to evaluate the influence of physical training on tocopherol and insulin concentrations in the blood plasma of rats treated with different doses of vitamin E. The concentrations of alpha-tocopherol (HPLC-UV method used) and insulin (rat insulin specific RIA method used) were estimated in the blood plasma. Lower concentration of vitamin E in physically trained animals was observed, which may suggest increased needs of organisms for antioxidants, as a result of increased free radical production. In trained rats a lower concentration of plasma insulin was also observed. This effect is probably related to improvement in insulin action observed in organisms under physical exercise. The most significant impact on plasma alpha-tocopherol was due to its supplementation level. The treatment of rats with different doses of alpha-tocopherol was found to be not related to insulin concentration in plasma. A significant increase in feed conversion factor was noted in vitamin E treated animals. The obtained results suggest that the increased requirement of trained rats for antioxidants might be covered by alpha-tocopherol supplementation.

The influence of dietary vitamin A supplementation on vitamin A and insulin levels in sedentary or physically trained rats.

Male rats of Wistar strain (n = 48) were fed a vitamin A deficient diet for 3 days of adaptation period and then a 10 day experimental period to reduce slightly the body stores of this vitamin. Half of the animals were subjected to physical training and/or oral vitamin A supplementation. Four different doses of supplementation were used--0, 7.5, 15 and 60 microg/d/rat, which is equivalent to 0, 25, 50 and 200 IU of vitamin A, respectively. Animals from the defined groups ran on a treadmill with a rate of 2.0 m/s for 15 minutes per day for 10 days. After overnight fasting, the rats were sacrificed, and insulin in blood serum and hepatic retinol concentrations were estimated. Daily feed intake and daily body gains were similar in groups of sedentary and physically trained rats. A moderate level of oral vitamin A supplementation (the highest supplemented dose was about 6 x the above recommended NRC level) did not cause any changes in these zootechnical parameters. Oral Vitamin A supplementation resulted in an increase in retinol concentration in the liver (F = 15.2, p < 0.001), but without significant difference between trained and untrained animals. Physical training of rats caused a statistically significant decrease of insulin concentration in blood serum (1.53 +/- 0.18 vs. 1.73 +/- 0.20). This difference was highly significant (F = 11.1, p < 0.001). Vitamin A supplementation was found not to influence the concentration of this hormone, which is responsible for energy metabolism regulation in the body. Based on estimated parameters, the necessity of vitamin A excessive use in physically trained subjects was not proven.

[Nitrates and nitrites and the utilization of beta-carotene. II. Determining the threshold of the tolerated dose of nitrates and nitrites in the diet of rats receiving beta-carotene]. / Azotany i azotyny a wykorzystanie beta-karotenu. Cz. II. Ustalenie granicznej tolerowanej dawki azotanów i azotynów w diecie szczurów przy podawaniu beta-karotenu.

The limit levels of potassium nitrate and sodium nitrite were determined in the diet of rats receiving orally beta-carotene. Two 30-day biological experiments were done on male Wistar rats standardized for vitamin A level in the liver. The animals were given semisynthetic diet, without vitamin A, containing definite amounts of potassium nitrate or sodium nitrite: 4.0; 4.5; 5.0; 5.5; 6.0% of the nitrate, and 0.5; 0.6; 0.7; 0.8; 0.9; 1.0% of the nitrite. The rats were given also orally two drops of an oil solution of beta-carotene in doses of 30 micrograms per rat daily. The limit of tolerance was established measuring beta-carotene utilization according to the method of balance studies and liver function test. Diet consumption and body weight of the animals were considered as well. It was found that in this experiment the limit dose, that is the dose of nitrates and nitrites over which the rats died, was 5.0% for nitrate and 0.7% for nitrite.

[Nitrates and nitrites and the utilization of beta-carotene. I. The effect of different amounts of dietary nitrates and nitrites on the utilization of beta-carotene in rats]. / Azotany i azotyny a wykorzystanie beta-karotenu. CZ. I. Wplyw zróznicowanch ilosci azotanów i azotynów zawartych w diecie na wykorzystanie beta-karotenu przez organizm szczura.

The subject of the study was demonstration whether and in what extent different amounts of nitrates and nitrites in the diet affect the utilization of beta-carotene by rat organism. The level of vitamin A in the liver was accepted as an indicator of this utilization in accordance with the method of combined balance studies and liver test; additionally the plasma vitamin A level was determined. Two biological experiments lasting 30 days were carried out on male Wistar rats standardized with respect to hepatic vitamin A content. The animals were given orally 30 mcg daily an oil solution of beta-carotene and diets with varying amounts of potassium nitrate (0.5; 1.0; 2.0; 4.0; 6.0%) and sodium nitrite (0.05; 0.1; 0.5; 1.0%). Nitrates and nitrites in the diets reduced the utilization of beta-carotene in a dose-dependent way. The nitrate reduced the utilization of the provitamins by from about 50% to over 60%, and the nitrite reduced it by from over 60% to about 80%. The studied compounds exerted also a negative effect on the consumption of diet and weight gain.

[Evaluation of nitrate and nitrite content in diets of preschool children]. / Ocena zawartosci azotanów i azotynów w posilkach dzieci przedszkolnych.

The nitrate and nitrite contents in diets of preschool children were evaluated. The meals were taken from one of the kindergarten near Warsaw. Colorimetric method with Griess reagent and cadmium column for nitrates reduction was used. It was seen, that diets contained to much of nitrates and nitrites as to ADI. The main sources of these compound were vegetables, potatoes, meat and meat products and cereals.

[Effect of nutrition education on nutrition behaviors of investigated students' group]. / Analiza wplywu edukacji zywieniowej na zachowania zywieniowe wybranej grupy studentów.

The aim of the study was evaluation if nutrition education effect on food consumption in students. The group of 110 students, 50% from Faculty of Human Nutrition & Home Economics and other from Horticulture Faculty was investigated. Food consumption quality was estimated using 24 hours recall method and modified by Kulesza test of Bielinska. It has been shown, that nutrition education did not significantly effect on food consumption of students.

[Evaluation of food consumption and nutritional status of children at preschool and school age based on the literature in 1980-1995]. / Analiza stanu zywienia dzieci w wieku przedszkolnym i szkolnym w oparciu o istniejace pismiennictwo z lat 1980-1995.

The study includes a survey of literature reports from the last 15 years on the consumption of food and nutritional status of preschool and school children. The nutritional status of preschool and school children suggested many shortcomings independent of social class and nutrition type (individual, mass nutrition). Generally, the nutrition of town children was better than that of rural children, and signs of deficiency of certain vitamins and mineral components were found in a lowe per cent of the former children. The food rations of the studied children contained too low consumption of milk and dairy products, vegetables and fruit, with high intake of fats, meat and its products, sugar and sweets. The daily food rations contained low amounts of calcium, vitamins A, B and C, with excess of phosphorus and fats. The nutrition of school children depended on year season, social class and education of parents. The most frequent faults included inappropriate timetable of meals, their poor quality, inadequate number and monotony. No such data could be obtained with respect to preschool children. The nutritional status of preschool and school children gives rise to objections, especially in the case of rural areas. There is a need to evolve and introduce a standardized study method for the assessment of nutrition and nutritional status of preschool and school children and continuous monitoring in this respect.

[The in vitro effect of ascorbic acid on sodium nitrite intoxication]. / Okreslenie in vitro dzialania kwasu askorbinowego przy intoksykacji azotynem sodu.

The in vitro effect of ascorbic acid on the content of sodium nitrite in relation to pH and time of incubation and also effect of sodium nitrite on the total content of vitamin C as a sum of both reduced and oxidized forms was demonstrated. Ascorbic acid in respective quantities of 60 mg, 120 mg, 180 mg and sodium nitrite in quantity of 12 mg were added to the in vitro simulated stomach content at pH 1.5, 2.5, 3.5. The control samples were tested without addition of ascorbic acid. The Griess method for determination of nitrite and the Tillmans method with Pijanowski's modification were used for the determination of vitamin C. It was found that the choice of lower pH significantly decreased the level of nitrite in the control samples produced the disappearance of nitrite increased depending on the quantity of ascorbic acid added to the sample and on pH. The total content of vitamin C did not change after adding of sodium nitrite to the samples. The performed studies suggested a positive effect of ascorbic acid decreasing of the nitrite level.

[Comparison of some enzymatic methods for dietary fiber determination in foods]. / Porównanie wybranych enzymatycznych metod oznaczania blonnika pokarmowego w zywnosci.

Comparison of three different enzymatic techniques for dietary fibre determination (Hellendoorn, Asp, AOAC)) in five kinds of food (white bread, rye rolls, white cabbage, carrot and red beet) was the main purpose of this study. It was found that our results obtained by Hellendoorn's method are overestimated and therefore are somewhat doubtful. For this reason the AOAC method can be recommended as more accurate.

[Frequency of intake and energy value of breakfast for students from selected primary schools in Warsaw]. / Czestotliwosc spozywania i wartosc energetyczna sniadan uczniów wybranych szkól podstawowych w Warszawie.

Energy value and frequency breakfast intake in Warsaw primary schools were estimated in a group of 330 children aged 7-15 years. The research was carried out in autumn 1998 year. The nutrition mode was assessed by questionnaire interviews and of 24-hour recall [4] and computer programme "Zywienie". The size of the consumed portion was determined with an album containing colour photographs of products and dishes of different size [14]. Food consumption quality was estimated using test of Bielinska modified by Kulesza et al. [8]. Frequency breakfast intake decreased at older schoolchildren. Breakfast milk and products, vegetables and fruits intake was too low; intake of fat sweets and beverages like "coca-cola" was too high. Breakfast energy value was too low compared with recommended dietary allowances.

[Determination of the dietary fiber content of some foods using a biological method]. / Oznaczanie blonnika pokarmowego w wybranych produktach spozywczych metoda biologiczna.

The evaluation of a biological method for dietary fibre determination in food was the main purpose of this study. Three-week old Wistar rats were used in this experiments. The rats were administered during two weeks a diet containing 1% of crude fibre from bread, grits, green beans, white cabbage and carrot. It was found that the biological method gave results similar to those obtained by the enzymatic one.

[Evaluation of beta-carotene bioavailability from selected vegetables grown by conventional and ecologic methods]. / Ocena biodostepnosci beta-karotenu z wybranych warzyw uprawianych konwencjonalnie i ekologicznie.

The availability of beta-carotene was studied from carrots and sorrel grown by conventional and ecological methods. The vegetables were bought in the market and in a shop with ecological food, and they had Ekoland atests. The bioavailability was determined by the hepatic test. No significant effect of growing method of the studied vegetables on beta-carotene bioavailability was found.

[Evaluation of nitrate, nitrite and total protein content in selected vegetables cultivated conventionally and ecologically]. / Ocena zawartosci azotanów i azotynów oraz bialka ogólem w wybranych warzywach uprawianych konwencjonalnie i ekologicznie.

Nitrates, nitrites and total protein content in selected vegetables from conventional and ecological farms were estimated. The beetroots, carrots, potatoes available on market or special shops in January, May and March were evaluated. The content of nitrates and nitrites was determined by colorimetric method with Griess reagent after previous reduction of nitrates to nitrites by metallic cadmium. Total protein content was determined by Kjel-Foss Automatic 16210 analyser working on the basis of classical Kjeldahl method. The higher content of nitrates was found in vegetables from conventional farms. Amounts of nitrates in both groups of vegetables did not exceed allowed limits. Levels of nitrites in ecological and conventional vegetables were similar-above 0.5 mg NaNO2/kg (except conventional potatoes from January). Slightly more content of protein was recorded in conventional vegetables.

[The evaluation of nitrates and nitrites food intake among Polish households in 1991-1995]. / Ocena pobrania azotanów i azotynów z zywnoscia w gospodarstwach domowych w Polsce w latach 1991-1995.

The studies on nitrates and nitrites food intakes in year 1991-1995 were carried out in four types of households i.e. works, worker-farmers, farmers, pensioners and retired persons and from 1993 in self-employed households and families maintaining themselves on non-income sources; altogether and with regard to the number of persons in family. Using household budget data and literature concerning nitrates and nitrites contents in food products, mean and maximum food intakes of these compounds were calculated and compared to acceptable daily intake (ADI) taking into consideration main sources of them. The obtained results indicated that the mean nitrate and nitrite food intakes did not exceed ADI but maximum intakes of one were several times higher than ADI. Nitrate and nitrite food intakes depended on type of household being highest at farmers, pensioners and the number of persons in family. Six persons families took nearly half less than did one-person one. There were no differences in main food sources of nitrates and nitrites for all types of households and number of person in families. Vegetables and their products supplied 94-98% of nitrates whereas meat products supplied 98% of nitrites.

[Effect of exercise on vitamin A utilization by rats]. / Wplyw wysilku fizycznego na wykorzystanie witaminy A przez organizm szczura.

The effect of exercise was studies on vitamin A utilization by rat organism. The biological experiment was done using 64 growing Wistar rats with initial vitamin A levels in the liver 380 and 790 i.u. The rats were subjected during 12 days to 30, 60 and 90 minute exercise on moving track at 20 m/min speed. The rats were exercised in groups. During the experiment they were given water and food ad libitum but without vitamin A, for controlling its intake. The measure of vitamin A utilization by rat organism after its addition to the diet was determination of its level in plasma, liver and kidneys. No evident differences were found in diet intake and body mass and in vitamin A levels in plasma and kidneys in the groups of rats differing in exercise duration. Increased duration of the exercise reduced vitamin A content in the liver, and this reduction was significant in the group subjected to exercise during 90 minutes daily.

[Values of nitrates and nitrites in selected vegetables given to hospitalized children]. / Zawartosc azotanów i azotynów w wybranych stosowanych w zywieniu dzieci hospitalizowanych.

In the study the levels of nitrates and nitrites were determined in certain vegetables used in preparation of meals for hospitalized children. The material studied comprised vegetables taken in three seasons of the year: autumn, winter, spring. Nitrates and nitrites were determined by the colorimetric method with Griess reagent after previous reduction of nitrates to nitrites with metallic cadmium. The content of nitrates, over 1 g NaNO3/kg, was found in celery, beet-roots, lettuce, green leaves of parsley and cabbage, even up to 10 g NaNO3/kg, in winter and spring in onions, leek and potatoes, and in autumn and spring in carrots. In 85% of the determinations the nitrite level was below 5 mg NaNO2/kg. An important source of nitrates in the food rations of the hospitalized children throughout the whole investigation period was lettuce, in autumn potatoes, in winter carrots and celery, and in winter and spring beet-roots.