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Biomedical subjects

M Kirchgessner

Publications and source records attributed to M Kirchgessner.

At least 289 records · Page 16Linked to original sources
PubMed1978

[Effect of graduated protein supply (0-50%) on hematologic values as well as protein and urea concentrations in the plasma of rats].

The influence of graduated protein supply (0-50% casein) on hematological values was studied in growing rats and compared with other criteria of the supply status. The following results were obtained: Weight development was found to reflect to 30%, the plasma protein content to 40% the level of protein supply. The highest protein levels revealed a trend towards lower values. At a dietary protein content of 15 to 20%, the urea concentrations of plasma went through a minimum. Both with better and with poorer protein supply they proved higher thus suggesting an increasingly energetic conversion of the feed protein. The hematological values hemoglobin, hematocrit and erythrocyt number responded uniformaly to the level of protein supply. This is also attributable to the close statsitical relationship between these three magnitudes. Whilst at the end of the experiment the erythrocyt number with protein-free diet proved lowest, the smallest values for hemoglobin and hematocrit were observed with 5% protein. From 10% on the differences were not so marked. Especially high values were measured, however, for all criteria at 40 and 50%, partly at 25% protein. As the calculation of the mean cell volume (MCV) revealed, insufficient protein supply is likely to affect rather the erythrocyt ripening than iron conversion. In agreement with this idea, the mean corpuscular hemoglobin concentration (MCHC) was not found to be influenced by protein supply.

Animal Feed↗
PubMed1978

[Zinc anabolism during pregnancy].

In the livers of pregnant rats an anabolic effect was found for zinc which, however, developed analogously to the enlargement of the organ. Femur and muscle did not reveal any super-retention of zinc during pregnancy. In the whole organism, a 10% increased zinc storage was found being attributable to stronger accumulation in the reproductive organs (3%) and in the liver (1%) and in other organs (6%) that were not under study. Higher Zn supply did not allow to increase this additional zinc storage during pregnancy. After lactation, the anabolic effect in the livers had declined, the Zn values of the lactating rats remaining, on the whole, at the same level as those of the pregnant animals. The Zn-serum concentrations as well as the alkaline phosphatase and carboxy peptidase A activities of the pancreatic gland were reduced during pregnancy, whilst the alkaline phosphatase activity in the femur increased. This finding is discussed in relation to Zn-supply and Zn-mobilisation.

Alkaline Phosphatase↗
PubMed1978

[Effect of various protein levels in the diet on the activity of some metalloenzymes].

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.

Alkaline Phosphatase↗
PubMed1978

Homeostatic adjustments in zinc digestion to widely varying dietary zinc intake.

A 15-day Zn balance study was conducted with 36 growing rats maintained on a casein diet with 18.2 microgram Zn/g from day 0 to 3. Thereafter, six rats each were given the diet with the following variates of Zn content (microgram Zn/g): 5.6, 10.6, 18.2, 39, 70, 141. Zn digestion adjusted to the change in dietary Zn intake within the first 6 days via control of the extent of intestinal Zn absorption and fecal excretion of endogenous Zn. From day 9 to 15, mean apparent Zn digestion ranged from 92 to 18% and Zn absorption from 100 to 34% in an inverse relation to Zn intake. At the supply of 39 and 70 microgram Zn/g of diet, fecal excretion of endogenous Zn amounted to nearly one fourth of the dietary Zn intake. Reduction of intestinal absorption became the major factor to confine Zn accretion by the body when Zn intake was in great excess above requirement. Endogenous fecal Zn excretion exhibited its greatest homeostatic response in the range of optimum Zn intake. Zn excretion via the kidneys did not partake in Zn homeostasis, except that it was a major drain of body Zn compared to the intestinal route at low Zn intakes.

Animals↗
PubMed1978

[Arginase activity in the liver of growing rats with manganese deficiency].

Rats weaned early at 13 days of age exhibited at 10% lower growth within 6 weeks when Mn supply was deficient compared to control animals (P is less than 0.005). While the reduction of the dietary Mn content from 50 to 6 ppm did not yet affect growth, the animals already showed a 60% lower arginase activity at this median level of Mn supply. The values of the depleted animals (0.7 ppm Mn) had fallen by 71% compared to the control group. Therefore, the arginase values may be applied to differentiate between suboptimum and optimum Mn supply.

Animals↗
PubMed1977

[Effect of storage on the vitamin B6 activity of foods (author's transl)].

In a study of the effect of storage on the vitamin B6 activity of foods, the vitamin B6 content of different foods of plant and animal origin and also of a mixed feed with added pyridoxine were analyzed microbiologically using Saccharomyces carlsbergensis as test organism. Vitamin B6 activity was determined initially, in some of the specimens after storage for 10 months and again in all foods after 40 months. The storage period of 10 months caused a loss of the natural vitamin B6 content of about 25--30%. This loss increased to more than 50% after 40 months storage. The diet containing the high level of synthetic pyridoxine lost 85% of its vitamin B6 content.

Animal Feed↗
PubMed1977

[Estimation of the net energy using volatile acids produced in the process of in-vitro digestion with ruminal fluid].

47 types of green feeds and roughages were subjected to an in-vitro fermentation with dilute ruminal fluid. The volatile fatty acids produced in this process were determined quantitatively in accordance with the method of digestibility estimation proposed by Tilley and Terry (1963). An average of 5 Mol FFS (FFS=volatile fatty acids) was found per kg of dried feed, a value is also reported in the literature. The ratios of acetate to propionate to n-butyrate to iso-butyrate to n-valerianate were 64.2 : 25.4 : 6.6 : 0.8 : 1.5 : 1.5. In this ratio, propionic acid predominated so that acetic acid and n-butyric acid were misrepresented compared with the data of in-vivo measurements made for the corresponding foodstuffs. Consequently, it is only within certain limits that values of FFS concentrations obtained in vitro may be used for estimating net energy data, disregardful of the fact that the FFS are the main source of metabolizable energy in ruminants. The reliability index for an estimation of Starch Equivalents and NEFr based on the above-mentioned method was found to be considerable lower (0.71 and 0.80) than that based on in-vitro digestibility measurements (0.86).

Animal Feed↗