Advances in trace elements research in nutrition.
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Humans↗
Biomedical subjects
M Kirchgessner
Publications and source records attributed to M Kirchgessner.
Calmodulin, zinc and calcium concentration in tissues of zinc- and calcium-deficient rats.
To demonstrate the effect of zinc and/or calcium deficiency on calmodulin concentration and also the antagonistic behavior of zinc and calcium in metabolism, four groups of eight rats each were provided the following diets in equal amounts: group I, the basic diet with 63 ppm zinc and 0.88% calcium; group II, the calcium-deficient diet (0.0043% calcium); group III, the zinc-deficient diet (1.1 ppm zinc); and group IV, the combined zinc/calcium-deficient diet. The zinc-deficient diet significantly reduced the zinc concentration in serum (72%), femur (65%), pancrease (34%), muscle (23%), testis (11%) and brain (7%), and elevated the calcium concentration in testis (19%) and brain (24%), but did not affect calcium concentration in serum, pancreas and muscle. Likewise, calcium deficiency reduced the calcium concentration in serum (56%), femur (40%), pancreas (16%), muscle (43%), testis (19%) and brain (24%), and elevated the zinc concentration in femur (22%), although the zinc concentration in serum, pancreas, muscle and testis remained unaffected. Combined zinc and calcium deficiency elevated both the zinc as well as the calcium concentration in serum, femur and muscle, as compared to zinc or calcium deficiency alone. The alkaline phosphatase activity was reduced by 52% during zinc deficiency and was elevated by a factor of 2.5 during calcium deficiency. The calmodulin concentrations in muscle, testis and brain, as determined by radioimmunoassay, were elevated during both zinc as well as calcium deficiency, although this elevation could not be confirmed in every case.
Animals↗
Retention of lead in growing rats with varying dietary lead supplements.
144 female rats with a beginning weight of 35 +/- 3 g were fed for 23 days a half-synthetic diet with a lead content that varied over 18 concentrations (0.025 to 600 mg/kg). Absolute lead retention was calculated as total body concentration of lead in animals at the end of the experiment minus the average lead concentration in carcasses of reference animals that had been sacrificed at the beginning of the experiment. The relative retention was calculated with regard to lead intake. Absolute lead retention increased in association with a lead supply of 0.225 mg per kg diet, but decreased thereafter. Not until a lead concentration of 5 mg per kg diet was reached did lead retention rise again. Relative lead retention decreased exponentially with an increasing lead supply and finally approached a constant value. Live mass development and feed intake were not affected by an increase in lead supply. Altogether, these results demonstrate that lead metabolism is homeostatically regulated.
Aging↗
Effect of dietary lead intake on lead retention in adult rats.
132 female rats with a live weight of 177 to 224 g were provided over a period of 17 days a half-synthetic diet with a lead concentration of 0.4 mg/kg. Then 120 of the animals were divided into 15 treatment groups fed with a diet different in Pb content (0.02, 0.04, 0.08, 0.12, 0.22, 0.42, 0.62, 0.82, 1, 5, 10, 50, 100, 400 and 800 mg Pb2+ per kg) over a period of 29 days. The feed was rationed so as to provide the minimum energy maintenance requirement. Pb retention dependent on different lead supplies was determined by subtracting the Pb contents of carcasses of 12 reference animals sacrificed at the beginning of the experiment from the Pb content of carcasses of rats at the end of the experiment. Up to a Pb concentration of 0.42 mg/kg in the diet Pb retention fluctuated around zero. Then the retention was slightly positive up to 5 mg/kg Pb in the diet. Up to 10 mg/kg Pb in the diet Pb retention increased sharply. Concentrations of iron, copper, zinc, and manganese in carcasses were affected only slightly by the varying concentration of lead in the diet.
Animals↗
[Effect of dietary zinc deficiency on vitamin A and alpha-tocopherol metabolism in the rat].
In order to study the effect of alimentary zinc deficiency on vitamin A and alpha-tocopherol metabolism, weaned, male Sprague-Dawley rats with a mean weight of 48 g were divided into three groups. Zinc depletion animals (n = 7) were provided a half-synthetic, casein-based diet with a zinc concentration of 1.3 ppm; the pair-fed (n = 7) and ad libitum-fed (n = 6) control animals were given a diet containing 96 ppm zinc. After 24 days, the serum zinc level for depletion animals was 80% lower than the level for the two control groups, although the vitamin A, beta-carotine and tocopherol concentrations in deficiency animals and in pair-fed control animals did not differ significantly from one another. In comparison with adlibitum-fed control rats, however, vitamin A and beta-carotine concentrations in depletion and pair-fed animals were elevated. The zinc concentration in livers of deficiency animals was reduced only in comparison to the value for pair-fed control animals, while the vitamin A, beta-carotine and alpha-tocopherol concentrations in livers of zinc-deficient animals were reduced in comparison to the values for both of the control groups. Nevertheless, these changes are less likely a result of zinc deficiency per se, but rather are more likely a result of the lowered feed intake during zinc deficiency and the reduced growth.
Animals↗
[The nutritive defaunation of the rumen in ruminants].
Two promising methods to remove the ciliate protozoa of the stomach of ruminants by simple alterations in the feeding system were examined in vivo with lambs and heifers in the present investigation. The use of pelleted concentrates fed ad libitum and of milk, especially of milk fat (cream), turned out to be effective against protozoa when given after few hours of fasting. Milk led to the defaunation of a great proportion of the animals supplied all at once in an amount of 5-10% of rumen fluid volume. With cream the amount could be lower according to the higher fat content. Defaunation with concentrate was found to be not dangerous only for animals adapted to intensive feeding sufficiently. Additionally, a series of in vitro experiments were carried out to evaluate the reasons for the anti-protozoal effects of these methods. Concentrates rich in starch had toxic effects against protozoa, which mainly derived out of the depression in ruminal pH. The formed lactic acid had further effects irrespective of pH. The addition of crude fibre, especially of cellulose or lignin, reduced or prevented the anti-protozoal effects of concentrate fed ad lib. This was not so with the addition of buffers. With milk the included fat was shown to be responsible for the anti-protozoal effects, while the other main constituents of milk were of no importance.
Animal Feed↗
[The effect of a different protein supply with regard to quality and quantity on growth and serum growth hormone in weaned rats].
A two-factorially experiment was done over a period of 42 days using 32 male, weaned Sprague-Dawley rats in order to study the effect of insufficient protein supplementation, with regard to quantity and quality (13% protein in comparison to 18%, and an essential amino acid index of 64 in comparison to 92%, resp.), on weight development and serum growth hormone concentration. Qualitative protein deficiency had a greater adverse effect on weight development and feed utilization than did quantitative protein deficiency. Both test factors combined brought about the lowest body weight and poorest feed utilization. A lowered hematocrit value occurred only after quantitative protein deficiency. The serum urea concentration was elevated after protein deficiency due to poor quality protein; the serum protein concentration tended toward reduction in both the case of qualitative as well as in the case of qualitative-quantitative protein deficiency. After providing the animals poor quality protein, growth hormone levels in serum were reduced, whereas the concurrence of both factors of protein deficiency caused the growth hormone concentration in serum to rise to a value 4.2-fold of the control value.
Animal Feed↗
[Thermogenesis in humans after varying meal time frequency].
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.
Body Water↗
[Effects of a grain-rich feed mixture without trace element and vitamin supplement on different performance parameters of fattening pigs].
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Animal Feed↗
[Long term studies of the influence of the energy supply during pregnancy on body weight changes and reproductive performance in the sow].
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Animal Feed↗
Effects of lead deficiency on lipid metabolism.
The criteria of lipid metabolism in lead deficiency were determined. For this purpose an experiment was performed with Sprague-Dawley rats distributed in depletion and control groups. The depletion rats were fed an extremely low lead content diet (20 +/- 5 ppb), whereas the diet for the control animals was supplemented with 800 ppb Pb++. Dependent on generation, depletion influenced triglyceride content in serum and liver, phospholipid and cholesterol content in liver as well as the whole body fat of the offspring. The results indicate that in mothers the absorption of lipids is impaired. Consequently it is possible that the mothers do not excrete enough fat with milk leading to an energetical deficiency and therefore to reduced growth.
Animals↗
[Allantoin excretion of wethers in variations of raw protein and energy administration].
216 values of urinary allantoin excretion were received from 8 digestibility trials, which included 48 rations with different protein and energy content. Thus relations between allantoin excretion and food intake and ration composition, respectively, could be evaluated. Additionally variations in N balance were measured, since there is a close relation to allantoin metabolism. Fecal N excretion was elevated with increasing energy intake, but varied only slightly with modified N supply. Urinary N excretion and also N retention increased with higher N intake. On the other hand urinary N losses were reduced with increasing energy supply and part of the saved nitrogen was deposed into the body. There was a distinct increase in allantoin excretion with raised protein intake, when N supply ranged generally low. But with a daily supply of crude protein above 60 to 70 g there was no significant further response in allantoin excretion. Allantoin excretion increased linearly with higher energy supply. Several restrictions for conclusions on the extent of microbial protein production in the digestive tract estimated out of measured allantoin values were discussed.
Allantoin↗
[Effect of the Zn supply on alkaline ribonuclease activity in rats].
The purpose of this paper was to show whether the activity of the zinc-dependent enzyme alkaline ribonuclease in zinc-sensitive tissues allows conclusions to be drawn on the Zn supply status. For this 27 weaned male Sprague-Dawley rats were divided into three groups of 9 animals each. A Zn deficiency group, which was given a diet with a Zn content of 3 ppm ad libitum, was compared to a pair-fed and an ad libitum control group with a Zn content in the diet of 60 ppm each. After 22 trial days the animals were killed, and the zinc and protein contents as well as the activity of the alkaline ribonuclease in the serum, testicles, femur, urine, liver, and kidneys were determined. Although the Zn concentration in the serum, testicles, femur, and kidneys of the deficiency animals were significantly reduced, the alkaline ribonuclease showed an increased activity only in the kidneys, in the testicles the activity was reduced, and in the serum, femur, urine and liver it remained unchanged. The protein concentration in serum and femur was reduced because of Zn deficiency, whereas the decrease in testicles, liver and kidneys must be attributed to the reduced feed intake. The influence of the dietary Zn deficiency on the activity of the alkaline ribonuclease was therefore more the result of an altered feed intake and growth rate than a direct effect of zinc on the enzymatic system. Therefore the determination of the activity of the alkaline ribonuclease can be excluded as a parameter for the diagnosis of Zn supply and Zn deficiency.
Animal Feed↗
[Comparison of vitamin B6 status of gravid and nongravid rats with varying vitamin B6 supplements].
In a two-factorial experiment the influence of graded vitamin B6 supplements on the vitamin B6 status of pregnant and nonpregnant rats was examined. Additionally the question concerning a vitamin B6 super-retention in pregnancy should be investigated. The experiment was carried out with 69 female SPF-Sprague-Dawley rats. Nine rats served as controls and were killed at the beginning of the experiment. On the first experimental day half of the remaining animals were mated at an average body weight of 210 g. The rats were then divided into five dietary groups, each containing 6 gravid and 6 nongravid animals. Throughout the experiment the rats received a semisynthetic casein-starch diet, containing 1, 6, 12, 24, and 48 mg vit. B6/kg respectively. The trial ended at day 19 of pregnancy. Liver, right and left gastrocnemius muscle and the remaining carcass (without the intestinum and the reproductive product of the pregnant animals) were microbiologically analysed for their vitamin B6 contents. The vitamin B6 status of the liver, which contained an average of 8.4 micrograms vit. B6/g fresh matter (FM) was not influenced by pregnancy. In muscle and carcass, however, pregnancy caused significantly reduced vitamin B6 levels of 4.8 and 2.6 micrograms vit. B6/g FM. Compared to the concentrations of the nongravid animals the values of the gravid rats were decreased by 6 and 7% respectively. The vitamin B6 supply of 1 mg/kg diet caused significantly lowered vitamin B6 concentrations in muscle and carcass of all animals. Intake levels of more than 6 ppm vitamin B6, however, did not further improve the vitamin B6 status of these organs. The carcass was only poorly affected by the vitamin B6 supplementations. Significant differences in vitamin B6 concentrations were only found between the 1 and 48 ppm vitamin B6 treatment. The whole vitamin B6 pool of the maternal organism, except the reproductive product, decreased in pregnancy from an average of 651 to 596 micrograms vitamin B6. Because of these results a super-retention could not be proved for vitamin B6. Moreover, a recommendation for the optimal vitamin B6 requirement in pregnancy was derived from the present results. Accordingly a supply of 6 mg vit. B6/kg diet, equivalent to a daily intake of 80 micrograms vitamin B6, is thought to be adequate to ensure an optimal vitamin B6 status in pregnant rats.
Animals↗
[Effect of type of starch and quantity in rations on apparent and true digestibility of nitrogen and nitrogen balance in sheep].
In a digestibility trial 5 semisynthetic rations were fed in 3 periods to 10 male sheep to examine the effects on N balance, components of faecal nitrogen and N digestibility. The rations contained constant amounts of nitrogen but different contents of cellulose and two different types of starch (untreated and steamflaked). Content and type of starch did not show any noticeable effect neither on excretion of undigested dietary nitrogen nor on true digestibility. There could not be noticed any effects on the apparent N digestibility by changing contents of cellulose or untreated starch. If the rations contained steamflaked corn starch, the animals excreted more faecal nitrogen and therefore showed a lower apparent N digestibility. Especially the water soluble N fraction of the faecal nitrogen was clearly higher. Compensation took place through a lower N excretion with the urine. The reason for increased faecal N excretion may be higher microbial protein synthesis in the rumen. This was accented by the allantoin excretion with the urine.
Animal Feed↗
Utilization of zinc from picolinic or citric acid complexes in relation to dietary protein source in rats.
Young male Sprague-Dawley rats were divided in 18 groups of eight animals each and were fed ad libitum for 24 d a purified diet with 20% casein, whey protein or serum albumin as protein source. Each diet was supplemented with zinc picolinate, zinc citrate or zinc sulfate to a level of dietary zinc equal to 5 or 10 ppm. The source of zinc had no significant effect on zinc utilization with any of the three dietary proteins or at either dietary zinc concentration. With the 5 ppm Zn diet zinc concentration in the serum, but not weight gain or the zinc concentration in femur, testis or whole body was lower in rats fed the casein diet than in those fed the whey diet. Zinc concentrations in serum, femur, testis and whole body, but not weight gain, were lower in rats fed the casein diet than in those fed the serum albumin diet. With the 10 ppm Zn diet, zinc concentrations in serum, femur and whole body, but not weight gain nor zinc concentration in testis, were lower in rats fed the casein diet than in those fed either of the other diets. These results suggest that the reason for the lower utilization of zinc from cow milk in comparison to human milk may be the higher casein concentration in cow milk.
Animals↗
[Energy balance trials with a diet rich in fats in the human].
The effects of two diets equal in protein content (12% of energy) but different in carbohydrates (80% of energy) or in fat (68% of energy) were studied in a changeover trial with 6 healthy young subjects. Each person was 2 weeks on each diet. 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. At isocaloric supply of metabolizable energy no differences were found in the retention of N, C and energy. The heat production calculated by indirect calorimetry was not significantly different with both diets. The lower body weight during the high-fat diet was due to higher sodium and water excretion. The high-fat diet resulted in lower fecal and higher urine excretion of nitrogen, but because of a compensative response no difference in nitrogen retention was observed between the two dietary regimens. The plasma concentrations of cholesterol, glucose and uric acid were higher with fat-rich diet; those of triglycerides were higher with carbohydrate-rich diet. The results demonstrate that the composition of the diet did not influence the energy balance.
Adult↗
[Effect of varying vitamin B6 intake levels on the vitamin B6 status of fetuses and reproductive organs].
In order to study the influence of varying vitamin B6 intake levels on the reproductive performance and the vitamin B6 status of fetuses and reproductive organs, 30 pregnant rats (Sprague Dawley strain) were fed a semisynthetic casein diet supplemented with 1, 6, 12, 24 and 48 mg vitamin B6/kg throughout pregnancy. On days 19 of pregnancy the rats were killed. Fetuses, placenta, amniotic fluid, amnion, uterus and mammary gland were analysed microbiologically for their vitamin B6 content. Reproductive performance was not influenced by the dietary treatment. Vitamin B6 concentrations in fetuses, placenta and amniotic fluid of mothers treated with the low 1-ppm vitamin B6 diet were significantly decreased. At a vitamin B6 supply of 6 ppm, however, tissue saturation was already reached in these organs. Accordingly, the whole vitamin B6 retention in the reproductive product plateaued at an intake level of 6 ppm vitamin B6 at 37 micrograms vitamin B6 per animal. These results indicate therefore that a level of 6 ppm dietary vitamin B6 is sufficient to guarantee an optimum vitamin B6 status in the reproductive product, and higher vitamin B6 supplementations showed no further effect on the parameters investigated.
Amniotic Fluid↗