Biomedical subjects

M Kirchgessner

Publications and source records attributed to M Kirchgessner.

At least 37 records · Page 2Linked to original sources

PubMed1998

Effect of different degrees of moderate iron deficiency on the activities of tricarboxylic acid cycle enzymes, and the cytochrome oxidase, and the iron, copper, and zinc concentrations in rat tissues.

Severe iron deficiency results in complex systemic disorders e.g., including metabolism of energy and minerals. To investigate whether also moderate iron depletion may alter the activities of citric cycle enzymes and the cytochrome oxidase, the trace element status, and serum enzymes indicative of cell damage, this experiment was carried out with rats supplied with sub-optimal iron (9, 13 and 18 mg iron per kg diet) over a total of 5 weeks. The study included 3 pair-fed groups and an ad libitum group, fed with 50 mg iron/kg diet. All iron-restricted rats were classified as iron-deficient on the basis of reduced iron concentrations in body and iron-depending blood parameters. Body weight gain and catalase activity in kidney were lowered in rats receiving the lowest dietary iron level, exclusively. Rats fed 9 and 13 mg iron per kg diet had nearly 6- and 3-fold, respectively higher platelet counts in blood than their corresponding pair-fed controls. The activities of transaminases ASAT and ALAT, alkaline phosphatase, glutamate dehydrogenase and lactate dehydrogenase in serum which are indicative of cell damage were also markedly influenced by moderate dietary iron restriction, in which the enzyme levels in serum increased with intensifying iron depletion. Although, moderate iron restriction to young male rats was associated with marked alterations in iron status and serum enzymes, the activities of tricarboxylic acid cycle enzymes including malic dehydrogenase, fumarase, and isocitric dehydrogenase as well as cytochrome oxidase in liver remained largely unaffected. Only hepatic aconitase showed a somewhat reduction with iron depletion. Moreover, iron restriction was also accompanied with an accumulation of copper in liver which was significant for rats fed 9 and 13 mg iron per kg diet, whereas zinc status remained completely unaffected by moderate iron deficiency. It can be concluded, that a short-term moderate iron deficiency with ranging hemoglobin concentrations from 66 and 121 g/L, was accompanied with altered platelet counts, serum enzyme activities indicative of cell damage, and hepatic copper concentrations, but the activities of the tricarboxylic acid cycle enzymes and cytochrome oxidase in liver remained largely unaffected.

Alkaline Phosphatase↗

PubMed1998

[Regulation of energy balance and body weight during isoenergetic carbohydrate and fat supply in a long-term study in sows].

A respiration trial was conducted in 14 adult sows to investigate the energetic effects of a high carbohydrate and a high fat diet over a period of 21 weeks. The basal ration was mainly based on barley and soybean meal and covered 60% of the maintenance requirement for energy. The addition of starch (50% wheat starch, 50% maize starch) or fats (25% lard, 25% soybean oil, 50% olive oil) was 173 kJ/kgW0.75. All rations were calculated with reference to the initial weight of the sows and remained constant throughout the experiment. The animals were fed twice daily. Feces and urine were collected during the first and last part of the experiment over six days each. Forty eight hour measurements of the gas exchange were recorded five times in the course of the trial. Energy balances were calculated using an indirect calorimetry technique (RQ method) as well as the carbon nitrogen balance technique. All components of the energy balance (feces energy, urine energy, metabolizable energy, energy retention) showed no significant difference between the two treatments. The heat production of the animals was 413 +/- 31 with the starch diet and 412 +/- 36 kJ/kg W0.75 when the fat diet was fed. The mean weekly body weights of both treatment groups coincided in all phases of the experiment. Calculation of nutrient oxidation performed for diets and for animal metabolism revealed that only the carbohydrate balance was achieved, whereas the fat balance showed unrealistic results. The sensitivity of the nutrient balance method to measurement errors of the gas exchange has been discussed. The current results indicate that an equal supply of starch or fat energy acts identically in the long-term on body weight regulation and energy balance when overfeeding is not present.

Animal Feed↗

PubMed1998

[Energy utilization of retrograded starch by sows].

A total metabolism trial was conducted in eight adult sows to compare the energetic utilization, nitrogen balance, and passage rate of retrograded starch (RGS) with that of pregelatinized wheat starch (PWS). The starch was added at levels of 12 and 24 g/kg W0.75 to a basal ration that covered the maintenance requirement. Each animal received all four treatment combinations in a change-over design. At the start and end of the trial all sows were fed the basal ration alone. Feeding took place twice daily. During each 3-week metabolism period a complete balance measurement was performed for all animals, with 6 daily collections of feces and urine and a 48-h gas exchange measurement in a respiration chamber. The sows' heat production and energy retention were calculated by the carbon-nitrogen balance method and the RQ method. Digestibility and metabolizability of energy and energy retention were lower in the basal ration with RGS supplement than in the PWS supplemented ration. With regard to N exchange, sows supplemented with RGS excreted more N in the feces and less N in the urine, whereas N retention was equal with both rations. The production of CH4 was higher with RGS than after feeding pregelatinized wheat starch. When compared with the nonsupplemented basal ration, the fecal volume was unchanged with PWS but significantly increased with RGS. The feed passage, measured as the mean retention time of a marker in the digestive tract, was 86 h on the basal diet, falling to 75 h with PWS supplementation and 65 h with RGS. The utilization of the supplemented energy was 12% lower for RGS compared with PWS. This difference was due to a reduction in the digestibility and intermediate utilization of the energy. The amount of metabolizable energy was calculated as 16 kJ/g and the net energy as 12.5 kJ/g RGS. The results of the trial underline the importance of retrograded starch as a fiber type nutrient and the associated advantages for the bowel function. The energetic utilization on the other hand is only slightly lower than that of non-resistant starch; unlike pure fibrous feed materials, RGS can therefore not be regarded as a "low energy" substance.

Animals↗

PubMed1998

The effect of dietary vitamin E supply and a moderately oxidized oil on activities of hepatic lipogenic enzymes in rats.

Diets rich in polyunsaturated fatty acids (PUFA) are well known to suppress hepatic lipogenic enzymes compared to fat-free diets or diets rich in saturated fatty acids. However, the mechanism underlying suppression of lipogenic enzymes is not quite clear. The present study was undertaken to investigate whether lipid peroxidation products are involved in suppression of lipogenic enzymes. Therefore, an experiment with growing male rats assigned to six groups over a period of 40 d was carried out. Rats received semisynthetic diets containing 9.5% coconut oil and 0.5% fresh soybean oil (coconut oil diet, peroxide value 5.1 meq O2/kg oil), 10% fresh soybean oil (fresh soybean oil diet, peroxide value 9.5 meq O2/kg oil), or 10% thermally treated soybean oil (oxidized soybean oil diet, peroxide value 74 meq O2/kg oil). To modify the antioxidant state of the rats, we varied the vitamin E supply (11 and 511 mg alpha-tocopherol equivalents per kg of diet) according to a bi-factorial design. Food intake and body weight gain were not influenced by dietary fat and vitamin E supply. Activities of hepatic lipogenic enzymes were markedly influenced by the dietary fat. Feeding either fresh or oxidized soybean oil diets markedly reduced activities of fatty acid synthase, (FAS), acetyl CoA-carboxylase, (AcCX), glucose-6-phosphate dehydrogenase, (G6PDH), 6-phosphogluconate dehydrogenase, and ATP citrate lyase (ACL) relative to feeding the coconut oil diet. Moreover, feeding oxidized soybean oil slightly, but significantly, lowered activities of FAS, AcCX, and ACL compared to feeding fresh soybean oil. Activities of hepatic lipogenic enzymes were reflected by concentrations of triglycerides in liver and plasma. Rats fed the coconut oil diet had markedly higher triglyceride concentrations in liver and plasma than rats consuming fresh or oxidized soybean oil diets, and rats fed oxidized soybean oil had lower concentrations than rats fed fresh soybean oil. The vitamin E supply of the rats markedly influenced concentrations of thiobarbituric acid-reactive substances in liver, but it did not influence activities of hepatic lipogenic enzymes. Because the vitamin E supply had no effect, and ingestion of an oxidized oil had only a minor effect, on activities of hepatic lipogenic enzymes, it is strongly suggested that neither exogenous nor endogenous lipid peroxidation products play a significant role in the suppression of hepatic lipogenic enzymes by diets rich in PUFA. Therefore, we assumed that dietary PUFA themselves are involved in regulation of hepatic lipogenic enzymes. Nevertheless, the study shows that ingestion of oxidized oils, regardless of the vitamin E supply, also affects hepatic lipogenesis, and hence influences triglyceride levels in liver and plasma.

Animals↗

PubMed1998

Different degrees of moderate iron deficiency modulate lipid metabolism of rats.

Severe iron deficiency affects lipid metabolism. To investigate whether moderate iron depletion also alters lipid variables-including lipid levels in serum and liver, hepatic lipogenesis, and fatty acid composition indicative of an impaired desaturation-we carried out experiments with rats fed 9, 13, and 18 mg iron/kg diet over a total of 5 wk. The study also included three pair-fed control groups and an ad libitum control group, fed with 50 mg iron/kg diet. The iron-depleted rats were classified as iron-deficient on the basis of reduced serum iron, hemoglobin concentration, and hematocrit. All moderately iron-deficient rats had significantly lower cholesterol concentrations in liver and serum lipoproteins than their pair-fed controls. Rats with the lowest dietary iron supply had higher concentrations of hepatic phosphatidylcholine (PC) and phosphatidylethanolamine (PE), lower activities of glucose-6-phosphate dehydrogenase, malic enzyme and fatty acid synthase, and higher triacylglycerol concentrations in serum lipoproteins than the corresponding pair-fed control rats. Moderate iron deficiency also depressed the serum phospholipid level. Moreover, several consistent significant differences in fatty acid composition of hepatic PC and PE occurred within moderate iron deficiency, which indicate impaired desaturation by delta-9 and delta-6 desaturases of saturated and essential fatty acids. We conclude that lipid variables, including cholesterol in liver and serum lipoproteins as well as fatty acid desaturation, reflect the gradations of iron status best and can be used as an indicator of the degree of moderate iron deficiency.

Animals↗

PubMed1998

The energetic feed evaluation in Germany.

The paper describes the energetic feed evaluation systems for ruminants, pigs, poultry and horses presently used in Germany. During the last ten years the "Ausschuss für Bedarfsnormen" (AfB; Committee of Nutrient Requirements) of the "Gesellschaft für Ernährungsphysiologie" (GfE, Society of Nutritional Physiology) introduced new recommendations for energy requirements of domestic animals including national and international references. The energetic requirements were factorially deduced (demand for maintenance and various performances) under consideration of partial efficiency of utilized metabolizable energy (ME) for various performances (k-values). Except for lactating cows (Net Energy Lactation; NEL) the energy requirements of other ruminants as well as of pigs and poultry are given in ME. At present, the energy requirement of horses is still expressed as digestible energy (DE). Besides several energy requirements reported there are equations to determine and to calculate the energy content of feeds (GfE, 1986-1998) and corresponding tables with include the nutritive values of feedstuffs for various species. The energy content of mixed feeds may be estimated by specific equations.

Animal Feed↗

PubMed1998

[The effect of size reduction of corn silage on feed intake, milk production and milk composition of cows].

In three experiments (E1, E2, E3) maize silage of different physical structure and of different stage of maturity at harvest were fed to 24 (E1), 36 (E2) or 28 (E3) dairy cows. The cows were fed individually over an experimental period of five or six weeks. The maize silages had a mean DM content of 28% (E1), 32% (E2) or 36% (E3). At the stage of harvest, the stovers and the cobs had a mean DM content of < 22% (E1, E2) or 27% (E3), 40% (E1), 46% (E2) or 57% (E3), respectively. The maize was harvested with a chopping length of 4 and 8 mm (E1, E3) and of 6 and 8 mm (E2), without corn cracking (E1) or with and without corn cracking (E2, E3). The daily feed ration consisted of ad libitum offered maize silage, 1.7 kg DM hay, soya bean meal (E2, E3) and concentrate. The different chopping length of 4 mm, 6 mm or 8 mm had no effect on the maize silage intake in E1 and E2. In E3 the daily maize silage intake increased by about 1.2 kg DM per cow at a chopping length of 4 mm in comparison to 8 mm, whereas only the treatment with the combination of 4 mm chopping length and corn cracking showed a significant increase in DMI. The corn cracking improved the milk yield significantly (E2) or in a tendency (E3) at 2.0 kg (E2) or at 1.6 kg (E2), while the variation of chopping length had no effect on milk yield. The different physical structure did not influence the milk fat content with mean values of 4.65% (E1), 4.15% (E2) and 4.10% (E3), respectively. The milk protein content decreased in E2 feeding maize silage with a chopping length of 8 mm and corn cracking; but in E1 and E3 no effect was seen on protein content with mean values of 3.66% (E1) or 3.51% (E2).

Animals↗

PubMed1997

Dietary thiamin supply during lactation influences thiamin status in lactating rats and their offspring and the thiamin level in milk.

This study was conducted to examine the effect of dietary thiamin, ranging from deficient to excessive supplies, on thiamin status of lactating rats and their offspring, and the thiamin level in milk. Therefore, after parturition, rat dams were divided into eight groups of 10 each, and were fed diets with 0, 2, 4, 6, 7, 40, 350 and 3500 mg/kg thiamin over a total of 13 days during lactation. Milk for determining the thiamin concentration was obtained from day 6 and 13 of lactation. At day 14 of lactation rat dams and their offspring were used to ascertain the thiamin status including transketolase activity of blood, liver and brain, and thiamin concentration in body. Thiamin supplies ranging from deficient to excessive dietary concentrations influenced both the thiamin levels of the lactating dams and their offspring within 13 days. Lactating rat dams fed a thiamin-free diet and their offspring were classified as thiamin-deficient on the basis of growth retardation and a lower activity of transketolase in blood, liver and brain. Within these variables transketolase in blood has been shown to be most sensitive, and reached a plateau feeding 6 mg/kg thiamin. The concentration of thiamin in milk ranged between 0.1 and 19 mg/kg. The findings also show that dietary thiamin had the strongest effect on thiamin in milk obtained from day 6 and 13 of lactation, and a deficient or suboptimal supply with thiamin was therefore not compensated for an intensified transfer of reserved body thiamin into milk. Also thiamin levels in tissues and carcass, which did not show any clear-cut saturation characteristic, increased with increasing dietary thiamin, and this dose-dependence was more marked in blood and liver than in carcass.

Animals↗

PubMed1997

[Effect of various riboflavin supplementations during lactation on riboflavin levels in milk, liver and carcass in lactating rats].

The present study investigated the effect of various dietary riboflavin supplementations (0 to 4000 mg/kg) during lactation on riboflavin concentrations of liver, carcass (bled body without intestine and liver), and milk in the rat. The experiment was conducted until the 14th day of lactation; milk samples were drawn on the 7th and 13th day of lactation. Riboflavin concentrations of milk raised continuously with increasing riboflavin supplementation; in the range between 0 and 10 mg/kg riboflavin supplementation, there was a linear relationship, and in the range between 12 and 4000 mg/kg there was a logarithmic relationship between riboflavin supplementation and riboflavin concentration in the milk. Maximum riboflavin concentration of milk obtained by supplementation with 4000 mg/kg was twelve-fold higher than without riboflavin supplementation. For riboflavin supplementation up to 12 mg/kg, riboflavin concentrations in milk on the 7th day of lactation and that on the 13th day of lactation were not different. In contrast, in rats fed diets with higher riboflavin supplementation, riboflavin concentrations were higher by 25% in average in milk on the 13th day of lactation than in milk on the 7th day of lactation. Contrary to the milk, riboflavin concentrations in liver and carcass exhibited a saturation, which was achieved at a supplementation of 6 mg/kg (liver) and 10 mg/kg (carcass), respectively. Maximum riboflavin concentrations obtained at a supplementation of 4000 mg/ kg were 1.9- and 2.3-fold higher for liver and carcass, respectively, than concentrations obtained without riboflavin supplementation. The dose-response relationship using riboflavin concentrations of liver and carcass as response factors indicates a riboflavin requirement of 8 to 9 mg/kg for lactating rats fed a semisynthetic diet with 17.4 MJ ME/kg dry matter and 20.8% protein in dry matter.

Animals↗

PubMed1997

[Growth and carcass quality of carp (Cyprinus carpio L.) fed different cereals, lupin seed or zooplankton].

120 carp (Cyprinus carpio L.) with an average initial weight of 516 g, were kept in 20 tanks at a water temperature of 23 degrees C and given five different commercially practical diets to an end weight of approximately 1000 g. Four of the diets consisted of more than 50% of the traditional sole feeds wheat (W), rye (R), maize (M), or lupin seed (L), mixed with other ingredients to give diets with similar concentration of energy and crude protein. The fifth diet consisted exclusively of deep frozen zooplankton (Z). The fish were given a daily feed amount of 1.8% of bodyweight. The bodyweights of the carp on the cereal diets or the lupin seed diet were similar at the end of the experiment, after 105 days, (W) 995 g, (R) 916 g, (M) 979 g, (L) 979 g, but were significantly lower on diet (Z) at 659 g. Average OM digestibility coefficients for the diets were 77-79% for the cereal-rich diets, 68% for (L), and 75% for (Z). The contents of skinless fillet (average 38.7%), viscera (average 13.2%) and residual carcass (average 48.2%) were similar for the diets with cereals or lupin seed, while fish on diet (Z) had significantly lower fillet proportion (33.6%), coupled with an increase in residual carcass (53.0%). The chemical composition of the fillet, viscera and the residual carcass was also affected. Fish on diet (M) had the highest fat content in the whole body (14.5% of the FM), followed by those on diets (W) and (R) at 13.3% and 12.9%, while fish on diets (L) and (Z) had significantly lower fat contents at 10.7% and 8.2%. Protein contents in the whole body (% of FM) were for diets (L) 16.7%, (W) 16.4% (R) 16.3%, (M) 16.2%, and (Z) 15.5%.

Animals↗

PubMed1997

[The effect of wheat bran and green meal supplements on vitamin B6 metabolism of sows fed suboptimal vitamin B6 supply].

The aim of these investigations was to examine the influence of "natural fibrous feedstuffs" as wheat bran and alfalfa meal on criteria of vitamin B6 metabolism of adult sows subjected to a low vitamin B6 supply. Two experiments were conducted in two periods with 12 sows (180 kg BW) and 3 groups each. The supplements were in the first experiment 0 g, 225 g and 675 g wheat bran, and in the second experiment 0 g, 575 g and 1150 g alfalfa meal to a compound feed, low in vitamin B6 content. The criteria were fecal and urinary vitamin B6 concentration and excretion, vitamin B6 concentration in blood, hematological criteria, activity of aspartate aminotransferase in erythrocytes (EAST) and xanthurenic acid excretion in the tryptophan load test. Vitamin B6 concentration in feces amounted 10-12 micrograms/g DM and was neither influenced by quality or amount of the fibrous products. Vitamin B6 excretion was increased by each supplement and 60-70% of vitamin B6 was excreted via feces. Fecal vitamin B6 excretion was enlarged linearly by increasing fibrous supplementation. Bacterially fermentable substrates from wheat bran induced a higher bacterial vitamin B6 synthesis compared to cellulose.

Animal Feed↗

PubMed1997

[The effect of different high riboflavin supplements during pregnancy and lactation on performance and erythrocyte glutathione reductase activity of rats].

In two experiments with 160 female Sprague-Dawley rats the influence of various dietary riboflavin supplementations during lactation and during pregnancy and lactation were examined on food intake, body mass, reproduction, hematologic profile and the erythrocyte glutathione reductase activity coefficient (EGR-AC). In the first trial rats were fed a semisynthetic, riboflavin-deficient diet, based on casein and corn starch with various riboflavin supplementations during lactation (0, 2, 4, 6, 8, 10, 12, 40, 400, 4000 mg riboflavin/kg diet). In the second experiment the rats received supplements of 1 and 20 mg riboflavin/kg diet, respectively, during pregnancy. After parturition each group was divided into three sub-groups with riboflavin supplementations during lactation of 1, 5 and 20 mg/kg diet, respectively. Both investigations ended at the 14th day of lactation. Food intake was decreased significantly by 25% and 11% in the groups without riboflavin supplementation or 1 mg riboflavin/kg diet. In the same groups body mass was reduced by 11% and 4%, respectively. With regard to the reproduction parameters the riboflavin supply influenced only the litter mass at the 14th day of lactation and only lactational supply was relevant. In both trials the results of the hematologic profile showed no differences. In riboflavin deficiency (0 or 1 mg riboflavin/kg diet, respectively) the EGR-AC was increased significantly to 1.9 and 1.8, respectively. At the supplementation of 4-5 mg riboflavin/kg diet EGR-AC reached a plateau of 1.45, which was not improved by higher supplements. Concerning the whole reproduction cycle (trial II) there was a stronger influence of the actual lactation-supply on EGR-AC, on the other hand a riboflavin deficiency in pregnancy could be compensated only partially by an optimal supply in lactation. Therefore, based on the parameter EGR-AC an optimal riboflavin supply is recommended for each part of the reproduction cycle. By means of EGR-AC also the riboflavin requirement for lactating rats was derived. Feeding a semisynthetic diet (17.4 MJ ME/kg DM, 20.8% crude protein in DM) a supplementation of 5-6 mg riboflavin/kg or a total content of 6-7 mg/kg diet is recommended.

Animals↗

PubMed1997

Influence of vitamin C, vitamin E and beta-carotene on the osmotic fragility and the primary antioxidant system of erythrocytes in zinc-deficient rats.

The present study was designed to investigate the effect of antioxidant supplementation on the in vitro osmotic fragility of erythrocytes from zinc-deficient rats. Rats were fed either a zinc-adequate diet, zinc-deficient diet or a zinc-deficient diet enriched either with vitamin C or vitamin E or beta-carotene. Components of the primary antioxidant system of erythrocytes, parameters of hemolysis in vivo and indicators of liver injuries were also examined. In order to ensure adequate and identical food intake rats were force-fed by intragastric tube. The supplementation with antioxidants led to a marked improvement of the osmotic fragility without having influenced zinc status of the animals and components of the antioxidant system. The strongest effect was exerted by vitamin E. The rats fed the zinc-adequate diet (control group) showed unusually high values of erythrocytes osmotic fragility. Therefore there was no difference between control group and zinc-deficient group. A possible reason for this is discussed. Zinc deficiency led to a reduction of serum zinc concentration and alkaline phosphatase activity as well as to changes in the antioxidant system of erythrocytes characterized by a decrease of glutathione and an increase of glutathione S-transferase activity. Superoxide dismutase activity in serum decreased. There was no indication for hemolysis in vivo and for liver injuries.

Alkaline Phosphatase↗

PubMed1997

[Feed intake and milk production in dairy cows fed whole fat soybeans].

In two experiments (E 1, E 2) two different basic diets were fed to 36 diary cows with addition of 1 or 2 kg of full fat soya beans (SB) or without SB for six weeks. The cows were fed individually. The basic diet consisted of 49% grass silage, 23% maize silage and 21% hay, supplemented with 7% manioc (% DM) in E 1 and of grass, supplemented with 2.0 kg maize silage, 3.0 kg hay and 1.5 kg manioc (kg DM/cow.d) in E 2. The basic diet used in E 1 and the grass in E 2 were offered ad libitum. Further a mixture of 1 kg SB, soya bean meal and manioc (Treatment 1), a mixture of 2 kg SB and manioc (Treatment 2) and a mixture of soya bean meal and manioc (Treatment 3, control), respectively, was supplemented to achieve diets with equivalent concentrations of energy and protein. Depending on the daily milk yield a concentrate was fed to high yielding cows (> 21.5 kg milk in E 1 and > 25.0 kg milk in E 2, respectively). The addition of 1 kg SB increased the forage intake in both experiments by 1.2-1.5 kg DM/cow.d significantly, while the addition of 2 kg SB increased the forage intake only in E1 to the same extent. The mean total DMI was 19.2 kg in E 1 and 17.7 kg in E 2, respectively. The daily milk yield was not influenced by addition of SB. The average milk yield was 28.8 kg and 26.7 kg in E 1 and E 2, respectively. The milk fat content increased significantly in E 1 by 0.3-0.4% with no respect to the amount of the supplied SB (4.11% vs. 3.74%). In E 2 the milk fat content increased only slightly (3.84% vs. 3.74%). Milk protein content was not influenced in E 1, but decreased in E 2 after addition of 2 kg SB.

Animals↗

PubMed1997

Supplementation with vitamin C, vitamin E or beta-carotene influences osmotic fragility and oxidative damage of erythrocytes of zinc-deficient rats.

Dietary zinc deficiency in rats causes increased osmotic fragility of their erythrocytes. In this study, the influence of supplementary antioxidants (vitamin C, vitamin E or beta-carotene) on osmotic fragility, oxidative damage and components of the primary defense system of erythrocytes of zinc-deficient rats was investigated. Indicators of hemolysis in vivo were also examined. Five groups of 12 male rats were force-fed a zinc-adequate diet (control rats), a zinc-deficient diet or a zinc-deficient diet enriched with vitamin C, vitamin E or beta-carotene. Compared with the control rats, the rats fed the zinc-deficient diet without supplementary antioxidants had greater red blood cell osmotic fragility, higher concentrations of thiobarbituric acid-reactive substances and alanine, higher glutathione S-transferase activity, lower concentration of glutathione and activity of glutathione peroxidase as well as lower activity of superoxide dismutase in plasma (P < 0.05). Supplementation with antioxidants generally improved osmotic fragility in zinc-deficient rats without influencing zinc concentration or alkaline phosphatase activity in plasma, indicators of zinc status. At some of the hypotonic saline concentrations tested, vitamin C and beta-carotene significantly affected osmotic fragility. The zinc-deficient rats fed a diet without supplementary antioxidants had significantly higher concentrations of alanine in erythrocytes than the zinc-deficient rats supplemented with vitamin C, vitamin E or beta-carotene and had significantly higher levels of thiobarbituric acid-reactive substances in erythrocytes than the rats supplemented with beta-carotene. There was no indication of hemolysis in vivo in rats fed zinc-deficient diets. The results show that supplementary antioxidants decrease osmotic fragility and oxidative damage of erythrocytes in zinc-deficient rats.

Alanine↗

PubMed1997

Dietary thiamin supply during gestation effects thiamin status of lactating rats and their suckling offspring.

This investigation was designed to examine the effect of dietary thiamin supply during gestation on body thiamin status of lactating rats and their suckling offspring, and thiamin in milk from 1 to 13 days postpartum. Therefore, a study over two generations was conducted feeding 2, 6.7 and 20 mg/kg thiamin during gestation and 8 mg/kg thiamin during lactation. Rat dams receiving inadequate thiamin during gestation and their offspring were thiamin-deficient on the basis of reduced activity of transketolase in blood and erythrocytes, which did not reach completely the control level even two weeks postpartum. The thiamin intake during gestation influenced significantly the thiamin levels in tissues of the dams and their offspring. However, the observed dose-dependence remained only for the first days of lactation. The thiamin concentration in milk two days postpartum also reflected the nutritional thiamin status from the pregnant rats, in which the thiamin concentration raised continuously with the duration of the lactation cycle. The data indicate that an adequate thiamin supply during lactation can not completely compensate for an inadequate thiamin supply during gestation, and that necessitates a constant thiamin intake.

Animals↗

PubMed1996

[Pre-cecal digestibility of natural thiamine, riboflavin and natural pantothenic acid in the swine animal model].

The aim of the present investigations was to produce results about precaecal digestibility of naturally occurring thiamin, riboflavin and pantothenic acid from corn, wheat bran and dried skim milk. Precaecal digestibility is used as a quantitative measure for availability and was determined in ileorectomized growing pigs. Therefore, 6 female DL-pigs with a liveweight of about 30 kg were fitted with ileorectalanastomosis as end-to-side-anastomosis with preserved ileo-caeco-colic valve. The metabolism trials to collect the chymus quantitatively with these animals were carried out from the third week until 9 weeks after surgery in the liveweight range of about 40-70 kg. Precaecal digestibilities from corn, wheat bran and dried skim milk were for thiamin 87, 91 and 96%, respectively, with all values being significantly different. Riboflavin was 67, 62 and 94% precaecally digestible, the significantly different values for pantothenic ranged from 20 to 47 and 90%. "Availability" of native thiamin was higher than of riboflavin and pantothenic acid, which showed the lowest value of about 50%. The availability of the vitamins from the animal product was significantly higher than from vegetable products. The suitability of the method is discussed.

Animals↗

PubMed1996

[Bone marrow morphology and various hemolytic markers in growing rats with alimentary lead deficiency].

The effects of an alimentary lead deficiency on bone marrow morphology and several laboratory parameters of hemolysis were examined in two growth- and one generation-experiments with female Sprague Dawley rats. The animals were fed a semisynthetic casein-based diet supplemented with 0 ppb up to 800 ppb lead as Pb-II-acetat-3-hydrate. The evaluation of bone marrow did not show differences among the groups with different lead supply in the diet. Concerning the laboratory parameters of hemolysis it has been shown that the hemoglobin concentration of plasma and the lactate-dehydrogenase activity of serum were increased and the haptoglobin concentration of serum was decreased in the groups fed the diets poor in lead relative to lead-adequate animals. The activity of glutathione peroxidase and the glutathione concentration in red blood cells were increased in the groups fed the lead-deficient diet compared to lead-adequate groups. In conclusion, the study shows that the pancytopenia observed recently in lead-deficient rats is not caused by disturbed hematopoesis, whereas some parameters measured suggest that there exists increased hemolysis in lead-deficient rats.

Animals↗