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Journal ArticleDOI

Bestimmung der Verfügbarkeit von Zink im Stoffwechsel sowie Ermittlung des Zinkbedarfs mittels Aktivitätsänderungen von Zink-Metalloenzymen

01 Feb 1975-Archives of Animal Nutrition (Taylor & Francis Group)-Vol. 25, Iss: 1, pp 83-92
TL;DR: In this paper, the metabolic availability of zinc can be determined by measuring the level of activity of different metallo-zinc enzymes and a suitable model was established to determine the degree of metabolic availability.
Abstract: Data on the zinc requirements of animals vary widely with the type of diet or kind of zinc compound considered, as they are dependent on the kind of definition and estimation of mineral requirements used which, in turn, are based on the analytical content of the mineral in the diet. Actually, requirements for a particular trace element are the same for any diet provided differences in the rate of absorption and metabolic availability of the element are taken into consideration. A suggestion is made in the present paper to utilize changes in the activity of different metallo-zinc enzymes as a method for determining the degree of metabolic availability of zinc. Within the framework of a repletion trial young male rats were fed a semisynthetic casein diet containing 1.2 ppm of zinc for a 14-day period of zinc depletion followed by a 15-day repletion period during which the rats received a diet containing 4.5 ppm or 12 ppm of zinc. In this trial the pattern of activity of the alkaline phosphatase in serum and in the femoral bones was studied and the level of pancreatic carboxypeptidase A and B was estimated. The data thus obtained were compared with those of pair-fed control animals and control animals fed a libitum. (96 ppm of dietary zinc). The results of the present trial show the metabolic availability of zinc can be determined by measuring the level of activity of these metallo-zinc enzymes. A suitable model was established. Moreover, attempts have been made to show in which way the zinc demands of growing, full-grown, pregnant and lactating animals may be estimated by measuring changes in the degree of activity of these metallo-zinc enzymes. A definition is, in this case, given by that amount of zinc which allows for an optimum activity of the different metallo-zinc enzymes. Such data are applicable only to a particular diet or are valid only for a particular zinc compound. Principally, it is much better to relate the Zn requirements of the animal to the level of absorbable and metabolically available zinc. The present model has been suggested to provide a possibility for measuring the metabolic availability of zinc in the body.
Citations
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Journal ArticleDOI
01 Sep 1977
TL;DR: Interestingly, zinc in human nutrition that you really wait for now is coming, it's significant to wait for the representative and beneficial books to read.
Abstract: (1977). Zinc in Human Nutrition. CRC Critical Reviews in Clinical Laboratory Sciences: Vol. 8, No. 1, pp. 1-80.

126 citations

Journal ArticleDOI
TL;DR: Results of this study indicate that the hardened body prepared withαZnTCP is superior to that prepared with αTCP in promoting new bone formation due to the release of zinc ions and the optimum amount of zinc in the hardened bodies is about 0.03 wt % to avoid inflammatory reaction.

79 citations

Journal ArticleDOI
TL;DR: In this paper, the Gottinger Miniaturschwein gewinnt als Labortier immer mehr an Bedeutung, i.e., it wird in dieser Arbeit versucht, den mit dem Gottingers experimentierenden Forschern einen Uberblick uber Zucht.
Abstract: Das Miniaturschwein gewinnt als Labortier immer mehr an Bedeutung. Es wird in dieser Arbeit versucht, den mit dem Gottinger Minipig experimentierenden Forschern einen Uberblick uber Zucht, Haltung und Gewichtsentwicklung sowie uber die bestehende Literatur zu geben. Es wurden ferner Kreislaufuntersuchungen (EKG, Blutdruck und Herzschlagfrequenz) im Wachzustand durchgefuhrt, um mehr uber die Physiologie dieses Tieres zu erfahren. Im Vergleich zum Hausschwein weist das Gottinger Miniaturschwein ein gunstigeres Diastolen-Systolen-Verhaltnis auf.

39 citations

Journal ArticleDOI
TL;DR: The present review will attempt to indicate how the trace elements function within an animal’s overall metabolism by examining the functional roles of the Trace elements with a view to being able to identify subclinical deficiencies.
Abstract: Many of the early studies of the metabolism of the trace elements were aimed at providing methods of assessing the adequacy of intake of individual elements. This may be achieved either by estimating body reserves of the elements or by determining whether their essential functions are being adequately maintained. Newly-evolving methods of assessing reserves include, for zinc, studies of metallothionein concentrations in blood or urine (Bremner et al. 1987) and, for iron, immunoassay of plasma ferritin levels (Peter & Wang, 1981). However, since trace element reserves are only of value in ensuring adequate functional capacity, methods based on the former approach must be calibrated against functional criteria. Furthermore, it has become increasingly evident that adverse biochemical changes can occur before diagnostic signs of trace element deficiencies are apparent. Such defects include reduced candidacidal activity of neutrophils from copper and selenium-deficient rats, mice and cattle (Boyne & Arthur, 1981, 1986a), degenerative changes in pancreas of cattle with low Cu intakes (Fell et al. 1985) and restricted growth of many species when Zn intakes are inadequate. Increasingly, therefore, investigations will concentrate on the functional roles of the trace elements with a view to being able to identify subclinical deficiencies. In the past, investigators frequently studied the multiple roles of individual elements, but to understand their significance each must be seen as an integral part of a particular metabolic pathway. For this reason, the present review will attempt to indicate how the trace elements function within an animal’s overall metabolism. The reference in the title to early defects relates to the time-course of onset of a deficiency and it should be recognized throughout that this may correspond to depletion for only a few days in the case of Zn but at the other extreme may extend with manganese deficiency into a second generation.

18 citations

Journal ArticleDOI
TL;DR: In this article, the effect of increasing protein levels in the diet (0 to 50% casein) on hematological criteria was supplemented by experiments regarding the reaction of catalase, ceruloplasmin and alkaline phosphatase under such conditions.
Abstract: Studies on the effect of increasing protein levels in the diet (0 to 50% casein) on hematological criteria (v. Krziwanek et al., 1978) were supplemented by experiments regarding the reaction of catalase, ceruloplasmin and alkaline phosphatase under such conditions. A relationship was found between the activity of all 3 enzymes and protein supply. The catalase activity of the blood revealed a linear relationship with the protein level of the diet. The activity of the alkaline phosphatase was found to go up as the protein level of the diet increased reaching its maximum with weight development. The ceruloplasmin activity revealed an opposite behaviour. The results show that the application of these criteria for measuring the supply with and conversion of trace elements do not allow reliable statements but under constant experimental conditions. The catalase activity in the blood may give certain clues for assessing the quality and quantity of protein in the feed.

7 citations

References
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Journal ArticleDOI
TL;DR: A rapid method has been devised which requires only 5 c.mm.

2,921 citations

Journal ArticleDOI
TL;DR: Zinc in isolated soy protein is less available than that in casein, and addition of calcium phytate to casein-gelatin type diet had little or no effect on zinc availability.
Abstract: SummaryZinc in isolated soy protein is less available than that in casein. Zinc in a casein-phytic acid complex, which contains an amount of phytic acid comparable to that found in isolated soy pro...

303 citations

01 Jan 1970

289 citations

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How much zinc does Emergen C have in it?

Principally, it is much better to relate the Zn requirements of the animal to the level of absorbable and metabolically available zinc.