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Biomedical subjects

M Kirchgessner

Publications and source records attributed to M Kirchgessner.

At least 235 records · Page 13Linked to original sources
PubMed1980

[Zn-binding capacity of serum. A parameter for diagnosing marginal Zn deficiency (author's transl)].

In two experiments with male Sprague-Dawley rats, the influence of varying the dietary Zn content on per cent Zn-binding capacity of the serum was to be measured. In the first experiment, young rats were given, after a 14-day Zn depletion, the following diets with 1.3, 4, 6, 8, 10, 12, 20, and 100 mg Zn/kg DM for 2 weeks. Per cent Zn-binding capacity of the serum was 90% in the extreme deficiency range and decreased to less than 60% with increasing dietary Zn content, whereas the serum Zn content rose steadily with the Zn supply. Following Zn injection, per cent Zn-binding capacity of the serum significantly decreased to values around 70% in all animals of the groups given 1.3--12 mg dietary Zn. At 20 and 100 mg/kg of diet, per cent Zn-binding capacity of the serum was not affected by Zn injection. In the second experiment, per cent Zn-binding capacity of the serum was also found to depend upon Zn supply without prior depletion in rats of three different age groups with life weights of 50, 100, and 300 g. Under these experimental conditions, per cent Zn-binding capacity of the serum proved to be a good indicator for diagnosing alimentary Zn supply.

Animals↗
PubMed1980

[The influence of ceruloplasmin injections on the Cu- and Fe-metabolism of piglets].

In two experiments with a total of 56 piglets the influence of intravenous injections of ceruloplasmin (CP) on the 2nd and 4th day of their lives on criteria of the Cu- and Fe-metabolism was investigated. Due to the injections, the CP-activities and the Cu-concentration in the plasma increased, as a rule, more than in the untreated control animals. This effect was more distinct and longer recognisable after the injections on the 2nd day of life. Effects on the Fe-metabolism registered in a increased Fe-concentration in the plasma. Hemoglobin content, number of erythrocytes as well as the activities of blood catalase were in no case influenced by the injections.

Animals↗
PubMed1980

[Effects of iron supply and lactation on iron availability in intermediate metabolism].

The availability of iron in metabolism was determined in dependence on the performance after lactation had finished and on the level of Fe-supply of a total of 56 rats. The availability of iron of those animals which had reared young was, according to the increased requirement, high and decreased from 87 to 54% after increased doses of iron. The values of full-grown control animals were considerably lower and had a falling tendency from 52 to 36% after an increasing supply with iron. Because of the reduced utilization of iron after increased supply the gross requirement must be increased over-proportionally when the net requirement rises.

Animals↗
PubMed1980

[Deficient nickel supply and the content of calcium, magnesium and phosphorus inthe bone of growing rats].

Based upon studies on Ni deficiency with marked changes in intermediary metabolism, the recent investigation examined the extent to which deficient Ni supply affects the content of calcium, magnesium and phosphorus in rat femurs. In Ni deficiency the content of calcium and phosphorus was reduced, in the case of calcium even more so than accounted for by the decrease in bone weight. The result was Ca : P ratio of 1.8 : 1 in Ni deficiency compared with 2.0 : 1 in control animals. In the case of magnesium, however, the Mg concentration was increased by 45% in the bone fresh matter of the deficient animals. The reduced Ca retention in the bone is accordingly contrasted by an enhanced deposition of magnesium.

Animals↗
PubMed1980

Total true efficiency of zinc utilization: determination and homeostatic dependence upon the zinc supply status in young rats.

Total true efficiency of zinc utilization and its component factors, true absorption and metabolic efficiency, were studied in relation to dietary zinc supply in a 15-day experiment with 36 weanling rats in six groups. After day 3, the initial supply of 18.2 ppm zinc in the diet for all groups was changed to 5.6, 10.6, 18.2, 39, 70 and 141 ppm in groups 1 to 6, respectively. During the 6-day balance period after day 9, zinc intake was proportional to dietary zinc concentration. Mean daily rates of weight gain and apparent zinc retention increased from a near zero level in group 1 to a high plateau from group 4 to 6. True absorption rate steadily rose and reached about twice that of apparent absorption in group 6. This difference in rates was due to endogenous zinc excretion. Percent total utilization and percent true absorption steadily declined from a mean of about 100 in groups 1 and 2 to nearly 15 and 30, respectively, in group 6. Metabolic efficiency, reflecting true retention of absorbed zinc, similarly declined as percent true absorption did. The major conclusion was that not only the absorptive but also the metabolic efficiency greatly contributed to zinc homeostasis and total true efficiency of zinc utilization.

Absorption↗
PubMed1980

[Influence of copper in combination with other trace elements on the activity of trypsin (author's transl)].

The activity of trypsin was determined by using N alpha-Benzoyl-L-arginin-p-nitroanilid (L-BAPA) as a substrate, and adding either the elements Cu, Zn, Fe, Ni, and Co alone or in combination with copper in the concentration range of 0.9 x 10(-7) to 0.9 x 10(-4) moles Men+/l. Cu and Zn don't elevate the activity of trypsin but if they are added separately in very small concentrations. They lower the activity at higher concentrations. The other trace elements elevate the trypsin activity over the whole concentration range investigated. When copper is used in combination with the other trace elements there is no additional effect on trypsin activity. Here activities are somewhere in between the values when elements are added separately. A competing effect for the bounding sites of the trypsin is supposed. In this way it is possible to explain the non-linearity of the turnover rate curves of the experiments with the combined trace elements.

Benzoylarginine Nitroanilide↗
PubMed1980

[Influence of various trace elements on tryptic hydrolysis].

The rate of hydrolysis of the synthetic trypsin substrate N alpha-benzoyl-L-arginine-p-nitroanilide was determined from turnover rate curves, when the trace elements zinc, iron, cobalt, and nickel were added in the concentration range from 0.9 . 10(-7) to 0.9 . 10(-3) mol Men+/l. The enzyme substrate ratio was 1:50. An influence on the activity of trypsin, depending on the element used and on its concentration could be determined. Cobalt and iron accelerated the enzyme's capacity of hydrolysis at all concentrations used, whereas addition of higher but not toxic amounts of zinc or nickel resulted in an inhibition.

Arginine↗