Biomedical subjects

M Kirchgessner

Publications and source records attributed to M Kirchgessner.

At least 127 records · Page 7Linked to original sources

PubMed1991

Endogenous iron excretion. A quantitative means to control iron metabolism?

The effects of supplemental oral (0, 40, and 400 ppm) and parenteral iron (0 and 2.72 mg Fe iv given initially as a single dose) on iron absorption, excretion, and retention were determined in 30 rats. Endogenous fecal iron excretion was determined by the radioisotope dilution technique after im injection of 80 kBq Fe-59, using blood and certain body tissues as reference sources for the estimation of the specific activity (Bq Fe-59/micrograms Fe) of endogenous iron. The basal diet contained 3.6 ppm Fe. Fe(III)-hydroxide-polymaltose was used as the sole iron source in oral, iv, and im iron treatments. Iron balance as determined from day 14 to 20 of the experiment was not significantly affected by iv iron administration. Nevertheless, a temporarily reduced retention should have occurred, since differences in final body iron contents were lower than 2.72 mg, as compared to the respective untreated groups. Apparent iron absorption and iron retention increased with surplus oral iron, and the efficiency rates were highest with adequate iron supply (40 ppm). True absorption rates of iron were similar without any, and with 40 ppm Fe amounting 40 to 50% of the intake. In the iron deficient rats, half of the actually absorbed iron (about 16 micrograms/d) was lost by endogenous fecal re-excretion, and another 3 micrograms/d by the urinary route. Endogenous loss with feces and with urine increased with further oral iron supply, but at a considerably lower rate as total fecal excretion. Parenterally administered iron did not affect endogenous loss at all. The results indicate that endogenous excretion cannot be regarded as a means to eliminate excessive iron, and might actually be an inevitable loss.

Absorption↗

PubMed1991

Cellulose fermentation capacity of the hindgut and nitrogen turnover in the hindgut of sows as evaluated by oral and intracecal supply of purified cellulose.

Adult sows fed a constant amount of a basal diet received purified cellulose either orally at levels of 0 and 475 g/animal.d (Experiment 1) or intracecally at levels of 0, 285, 570 and 855 g/animal.d (Experiment 2). Each experiment consisted of subsequent periods of faeces and urine collection with the animals re-allocated to the treatments each time. With that, a total of 36 observations on each parameter was achieved. The faecal samples were analyzed for the contents of organic matter, cell wall carbohydrates and various nitrogen fractions such as bacterial N and undigested dietary N. Furthermore, N balance, urinary allantoin excretion and plasma urea concentrations were determined. In a preliminary study, the effects of freeze-drying and of shaking of the faecal samples as suspensions with water (in order to release bacteria from fibre) on content and composition of faecal nitrogen had turned out to be reproducible. Cellulose significantly enhanced faecal nitrogen loss whereas N retention was not affected due to the counteraction of urinary N loss. Plasma urea concentration reflected the situation with urinary N. The proportion of undigested dietary N and of water-soluble protein in total faecal N was somewhat increased by cellulose at cost of the bacterial N proportion which accounted for about 72% of total N on average. Urinary allantoin did not respond to the higher bacterial activity in the hindgut in the presence of supplementary cellulose. Cellulose significantly decreased the apparent N digestibility by on average about 3 percentage units per 100 g of supplementary cellulose. True N digestibility was also reduced by cellulose but did not go below 95%. The supplementary cellulose was fermented in the hindgut at similar rates of on average about 60% regardless of the route of administration. The almost 100 g of native cellulose incorporated in the basal diets were lignified by about 20%, and that is why they were fermented at a rate of only about 30%. The rate of fermentation was only slightly decreasing with increasing amounts of supplementary cellulose, and a daily quantity of 564 g (11 g/W0.75) cellulose was fermented on average if the highest level of cellulose was provided. This was within a range exclusively reported for easily-fermentable carbohydrates but was achieved in the case of cellulose only at a consistently higher level of supply. The true efficiency of bacterial protein synthesis was 5.2 g bacterial protein/100 g supplementary cellulose on average. The apparent efficiency was 60% higher averaging 8.4 g bacterial protein/100 g further apparently fermented organic matter.

Animals↗

PubMed1991

The role of experience in the development of selective zinc intake in pullets.

Selective food intake behaviour was studied in pullets that were subjected to different zinc supply in early life. During the first four weeks post-hatching three groups, totaling 72 birds, were fed either a low zinc diet (25 ppm), a complete diet (50 ppm) or both diets in a choice situation. The prior feeding experience was investigated during the subsequent ontogenetic development in two-choice dietary tests. Chicks first exhibited a preference for the high zinc diet as deficiency symptoms can be seen in depleted birds. Juvenile pullets did not prefer any diet for the duration of experimental period. Layers were initially indifferent to the supplemented zinc diet, but after reaching high laying capacity they began preferentially to select the complete diet. The results indicate that early experience with diets different in zinc content have no influence on subsequent diet preferences at choice. The ability to select is based on association learning following ingestion. A conditioned diet aversion first developed in phases of high zinc requirement as a result of negative feedback mechanisms produced by the deficient diet.

Animal Feed↗

PubMed1991

Energy metabolism of lactating dairy cows treated with prolonged-release bovine somatotropin or energy deficiency.

Two experiments were carried out with lactating Simmental x Red Holstein Friesian dairy cows. In the first experiment, 8 cows each received six injections at 4-wk intervals of either saline or 640 mg of prolonged-release bST. In the second experiment, 14 of 20 cows received 20 MJ NEL less than their daily requirement for 3 wk. Digestible and metabolizable energy were not affected by the treatments. Mobilization of body energy compensated the bST-induced increase of milk energy and supported milk production of underfed cows by two-thirds of the net energy deficit. The utilization of mobilized body energy and metabolizable energy from the diet for maintenance and milk production was unchanged. The bST and energy deficiency increased N utilization for milk production, because bST increased milk N secretion at the same N intake, and energy deficiency partly compensated the reduced N intake by N mobilization. Milk yield oscillated between the bST injections. Mean milk yield increased by 2.8 kg at constant milk composition. During energy deficit, milk yield dropped by 1.7 kg with decreasing milk protein content.

Animals↗

PubMed1991

Calmodulin activity in tissues of Zn- and Ca- deficient rats.

36 male Sprague-Dawley rats of an average body weight of 48 g were divided into 4 groups of 9 animals each. Group I was fed the basal diet with 63 mg/kg of Zn and 0.88% calcium, group II received a zinc-deficient diet (1.1 mg/kg of Zn), group III a calcium-deficient diet (0.0043%) and group IV a simultaneous zinc/calcium-deficient diet (1.1 mg/kg of Zn; 0.0043% calcium). All 4 groups received the diet in the same daily amounts, which was based on the food intake of the zinc-deficient group (II), in which food intake was reduced (as it also was in group IV) because of zinc deficiency. On day 28 all animals were killed and the calmodulin activity in the brain, muscles and testes was estimated. Calmodulin activity was determined by measuring the activation of a calmodulin-free phosphodiesterase against a calmodulin standard derived from porcine brain. Compared with the control animals zinc and simultaneous zinc/calcium deficiency reduced calmodulin activity in the muscles and testes, but not in the brain. Alimentary calcium deficiency did not influence calmodulin activity in the brain, muscles and testes.

Animals↗

PubMed1991

[Ergotropic effects through the nutritive use of organic acids].

Experimental data showed a significant improvement of growth rate and efficiency of feed utilization of young animals (piglets) by the dietary inclusion of organic acids. These ergotropic effects were mainly observed with citric acid, fumaric acid and formic acid as well as with Ca and Na formate. The merely dietary pH lowering with an inorganic acid (ortho-phosphoric acid) failed to show a nutritive efficacy. Studies on the mode of action of organic acids indicated a higher protein and energy digestibility, a lower stomach pH and reduced levels of NH3 and lactic acid in the stomach and duodenal digesta. Furthermore, the duodenum mainly contained a significant lower bacterial population for E. coli and enterococci. By this way the burden of metabolism of the host may be reduced which results in a higher overall performance.

Animal Feed↗

PubMed1990

Quantitative effects of allogeneic small-bowel transplantation on nutrient digestion and on body protein balance as determined in vivo in rats.

Heterotopic and orthotopic small-bowel allotransplantation was carried out in Wistar rats using grafts reduced to one-half of the original length. Portocaval venous anastomoses and intestinal end-to-end anastomoses were performed. Animals either with complete or with partially reduced native small-bowel served as control. In a total of 51 rats, 88 quantitative in vivo measurements of apparent digestion and absorption of dietary dry matter, organic matter, energy, protein, fat, total ash, and glucose were carried out. Body protein retention was calculated from intake and losses with feces and urine. The digestion trials comprised 8 days of adaptation and 10 days of continual recording of nutrient balance data. In experiments 1 and 2, digestibility coefficients were obtained before and after transplantation within the same animals, untreated or initially treated with cyclosporine A after surgery. Similar groups of rats untreated, with partial resection and with transplantation of the small-bowel, followed by temporary cyclosporine treatment, were used in experiment 3. In experiment 4, rats with transplanted intestines from experiments 1 and 2 were subjected to a further digestion trial 4 to 6 months after the respective first trial. With transplantation of the small intestine, apparent digestion and absorption of nutrients, as well as protein retention, tended to be lower. Significant depression occurred in the digestion of fat and ash. In long-term survivors all parameters decreased further. The adverse effects on fat and ash digestion seemed to be pronounced when rejection occurred. Fecal fat excretion might therefore be an indication of dysfunction of small-bowel grafts. Digestion was less imparied if cyclosporine was applied, and part of the effects on digestion and protein balance could be attributed to the shortened bowel.

Animals↗

PubMed1990

[Vitamin B1 content of liver, brain and muscles of pregnant and nonpregnant rats with different vitamin B1 supplies].

The purpose of this publication was to examine the effects of a wide variation of dietary vitamin B1 supply (0-12,000 mg vitamin B1 per kg diet) to gravid and non gravid rats on their vitamin B1 content in liver, brain and muscle. The experiment was designed with 176 (2 x 11 x 8) female Sprague-Dawley-rats. Additionally, the organs and tissues were tested as criteria for requirement recommendations. The animals were sacrificed on the 20th day of gravidity of the pregnant rats. Before gravidity the vitamin-B1-contents were 4.7 micrograms/g liver, 2.5 micrograms/g brain and 1.5 micrograms/g muscle. At the end of the experiment the gravid rats had a 19 per cent higher liver content than the non gravids. With a dietary supply of 8-10 ppm vitamin B1 the liver content plateaued until about 120 ppm. Vitamin B1 concentration in brain was about 2 micrograms/g and gravidity was of no effect. Vitamin B1 concentration in muscle was significantly influenced by both factors and saturation was reached at 1.3 and 1.7 micrograms/g muscle. These data showed that the response of the liver to dietary supply was the most sensitive and should therefore be considered in requirements. The requirement for non gravid animals is therefore 4 mg vitamin B1 per kg diet at minimum, gravid animals should be supplied by 7 mg per kg diet.

Animals↗

PubMed1990

Activity of Na-K-ATPase and Ca-Mg-ATPase in red blood cell membranes of lead-depleted rats.

Na-K-ATPase and Ca-Mg-ATPase activity of erythrocyte membranes from lead-depleted rats were determined. In P0 generation there was no difference in activity of Na-K-ATPase and Ca-Mg-ATPase between control and depletion rats. In contrast to this, in F1 generation lead-depleted rats showed reduced activity of both enzymes. Possibly, these changes of Na-K-ATPase and Ca-Mg-ATPase activity cause the reduction of the mean corpuscular cell volume (MCV) observed in former lead depletion studies.

Animals↗

PubMed1990

Retention and utilization of thiamin by gravid and non gravid rats with varying dietary thiamin supply.

The intention of this paper was to examine a retention of thiamin by gravid and non gravid rats and to test also whether there is an anabolism of the gravids. For this purpose a trial with 176 rats was designed in a two-factorial model (2x11x8) with the factors gravid versus non gravid and 11 different dietary thiamin concentrations of 0/0 (gravid/non gravid), 0.8/1, 1.7/2, 3.3/4, 6.7/8, 13.3/16, 20.0/24, 26.7/32, 100/120, 1000/1200, 10,000/12,00o mg thiamin per kg diet. The daily thiamin intake of the gravids and non gravids was the same. The experiment lasted until the 20th day of gestation. Liver, brain and musculus quadriceps, the reproductive organs and also the whole carcass were examined for their thiamin contents. At the beginning of the experiment 12 animals were sacrificed to get their starting contents. Liver thiamin retention was significantly influenced by the dietary supply, also by gestation and by the interaction of both factors. For the gravids, a mean daily anabolism of 1.5 micrograms occurred in the liver. In brain a negative retention of 4-8% occurred during the experiment, which was significantly less in the gravids. In muscle dietary supply was of significant influence, gestation, however, decreased muscle retention in gravids. In whole carcass the gravids retained 81 micrograms and the non gravids 61 micrograms (P less than 0.05). Anabolism occurred from 3.3 mg dietary thiamin per kg (46 micrograms daily intake) and plateaued at about 30 mg or 1.5 micrograms daily until 100 ppm dietary thiamin. Thiamin utilization remains below 10% in all groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Animal Nutritional Physiological Phenomena↗

PubMed1990

Biliary flow rate and concentration of Fe, Cu and Mn as affected by enteral or parenteral Ni supply.

Five and three bile duct cannulated 45 kg pigs were used in two experiments to evaluate the effects of nickel on the biliary excretion of iron, copper and manganese. In control periods the animals consumed 1.5 mg Ni per day (1 mg/kg diet), and in the respective treatment periods they further received 90 mg Ni per day (60 mg/kg diet) orally or 1.5 mg Ni per day intravenously. Oral supplementation of nickel had no significant effect on biliary iron, whereas the secretion rate of copper was increased by about 50%, and manganese secretion was reduced to about 50% of the control value. Parenteral administration of nickel had no significant effect on biliary iron, copper and manganese secretion. Iron and copper secretion rates were highest after feeding, whereas the pattern of manganese secretion was characterized by a predominant noctural peak irrespective of the treatments in both experiments.

Animals↗

PubMed1989

[The course of vitamin B6 content in growing rats during vitamin B6-free nutrition].

This experiment was designed in two parts. In the first part the vitamin B6 efficiency in response to increasing dietary vitamin B6 intakes was tested in growing rats; in the second part the reaction of rats, originally supplied with the fourfold requirement and then switched on the vitamin-B6-free basal diet was examined. The experimental animals were male Sprague-Dawley rats, of which weight gains, feed intake, and vitamin-B6-concentrations in blood, liver and whole carcass were measured. At the beginning of the trial nine animals were analyzed; 54 additional animals, divided into six groups, were given a vitamin-B6-free semisynthetic diet for three weeks which was supplemented with 0, 1.5, 3, 6, 12, and 24 mg vitamin B6 per kg feed. For the second part the additional 54 animals were given a diet with 24 mg vitamin B6 for three weeks and then switched to the vitamin-B6-free basal diet. Six animals per group were sacrificed after 2, 5, 8, 12, 16, 20, 25, 30, and 35 days of depletion. Efficiency of dietary vitamin B6 decreased from 38% at 1.5 mg vitamin B6 per kg diet to 4% at the 24 mg dietary level. Also, without dietary vitamin B6 the animals gained weight (from 145 to 300 g live weight), the daily feed intake increased from 14 to 19 g and feed efficiency decreased from 2.2 to 4.3 g feed per g gain. Vitamin B6 concentration in tissues reacted differently.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1989

[Variability and circadian rhythms of maintenance energy expenditure in adult humans].

Using indirect calorimetry the energy expenditure of healthy subjects was investigated as complete 24-hour balance measurements. The respective data were evaluated with regard to level, variation and normalizing of heat production (HP) and maintenance requirement. Diets were composed of customary ingredients and the intake of energy maintained constant slightly below maintenance requirement during the 14-day experimental period. Faeces and urine were collected for the final 7 days. Exchange of oxygen and carbon dioxide was measured during the last 48 h while the subjects stayed in an open-circuit respiration chamber, furnished like a small living-room. The daily energy balance averaged -0.38 MJ (+/- 0.73). For data evaluation the HP of each subject was corrected to zero energy balance, assuming a calorigenic effect of 10% for mixed diets. The resulting energy requirement of metabolizable energy for maintenance at energy equilibrium amounted to 136 (+/- 17) MJ/kg body weight and 383 (+/- 45) kJ/(kg body weight)0.75, respectively. Scaling the body weight to the 3/4 power diminished slightly the coefficient of variation. The observed total variance of the HP was mainly contributed by the subjects per se (94%), whereas only a small amount was related to day-to-day variability (6%; measurement noise and intraindividual variability). In terms of coefficient of variation the respective values were 11.5 and 2.8%. Comparable assessments with sows showed nearly the same results on animal variance and day-to-day variability. The daily time pattern of HP showed two maxima and two minima. In the morning and evening the HP exceeded the average 24 h value by 19 and 14%, respectively. During afternoon a value of 11% was observed. However, after midnight HP fell 31% under the daily mean. The relation between daily minimum and maximum was 1.7:1. During night the subject standard deviation was 8.6% compared to about 12% in the daytime. It is concluded that the total experimental error observed generally in whole-body indirect calorimetry studies is mostly attributable to subject variability. Furthermore, the variation of energy expenditure may account for deviations up to 10% or more between individual requirement and recommendations for predicting energy requirements.

Adult↗

PubMed1989

Influence of zinc and calcium deficiency on the concentrations of calcitonin, parathyroid hormone, and 25-hydroxy-vitamin D3 in rat serum.

48 male Sprague-Dawley rats with an average live weight of 141 g were assigned to four groups of 12 animals each. Group I was fed the basal diet (63 mg/kg of Zn, 8.8 g/kg of Ca), group II received a Ca-deficient diet (0.043 g/kg of Ca), group III was fed a Zn-deficient diet (1.1 mg/kg of Zn), and group IV received a diet with a combined Zn- and Ca-deficiency (1.1 mg/kg of Zn; 0.043 g/kg of Ca). Each of the four groups was fed the same daily quantity of rations, which was based on the food uptake of the deficient groups III and IV. After 28 days of the experiment, the rats were anesthesized with ether and sacrificed. In the obtained serum, the concentrations of calcitonin, parathyroid hormone, and 25-hydroxy-vitamin D3 were measured by radioimmune assays. The Zn- and Ca-concentrations in the serum served as parameters for the status of Zn- and Ca-supply. 1. Dietary Ca-deficiency had no influence on the development of live weight of the rats in the case of restricted feeding. Zn-deficiency, however, strongly reduced live weight development. 2. Alimentary Ca-deficiency reduced the Ca-concentration of the serum by 34%, the calcitonin concentration by 17%, and the 25-hydroxy-vitamin D3 concentration by 82% as compared to the levels in control animals, whereas the concentrations of Zn and parathyroid hormone remained unchanged. 3. Alimentary Zn-deficiency reduced the Zn-concentration of the serum by 63% as compared to the control animals, whereas the concentrations of 25-hydroxy-vitamin D3 and parathyroid hormone were increased.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1989

Studies on the determination of Na-K-ATPase in red blood cell membranes.

The present paper is concerned with Na-K-ATPase. In the first part it deals with the effect of such factors as Na+, K+, Mg2+, ATP, pH on activity investigated using a soluble Na-K-ATPase from porcine cerebral cortex. In the second part a method for assaying red blood cell Na-K-ATPase is described. This method consists of specific steps for washing and preparation of red cell membranes, pretreatment of Na-K-ATPase with sodium dodecyl sulfate (SDS) and bovine serum albumin (BSA) and determination of enzymatic released inorganic phosphate. Na-K-ATPase prepared and treated in this way shows a higher activity than the conventionally prepared form of enzyme, as latent enzyme sites are exposed by the SDS treatment. The kinetic behaviour of Na-K-ATPase prepared and assayed by using this method is characterized and compared with that of soluble Na-K-ATPase.

Animals↗

PubMed1988

[Effect of marginal zinc deficiency on humoral immunity in rats].

The purpose of this experiment was to examine the effects of a marginal zinc deficiency on serum immunoglobulin (Ig) IgM and IgG1 levels. 60 weanling female Sprague-Dawley rats were divided into six groups of ten animals each. Two control groups (73.7 ppm Zn) and two zinc-deficient groups (4.3 ppm Zn) were fed a semisynthetic casein diet ad libitum. The animals of two further groups received the control diet (73.7 ppm Zn) pair-fed to the zinc-deficient animals. After 15 days the rats of one group of each treatment were infected i.m. with a single injection (0.2 ml) of a bovine enterovirus, apathogenous to rats. 3 weeks later, all rats were anesthetized with ether and decapitated. Infection of the rats with the bovine enterovirus had no effect on the serum immunoglobulin level. The marginal zinc deficiency did not alter the IgM and IgG1 serum concentrations at all either. It remains to be examined whether other Ig-classes will react to marginal zinc deficiency. Also, the effect of severe zinc deficiency on the humoral immune system must be studied.

Animals↗

PubMed1988

Determination of endogenous manganese excretion in broiler chicks by an isotope-dilution method.

A tracer study with broiler chicks was conducted to determine endogenous Mn excretion in response to graded levels of dietary Mn supply by the isotope-dilution method. Starting with 46 day-old chicks, low-Mn diets were fed for 12 days before 8 chicks were slaughtered for assessing the initial Mn status and 38 chicks each were given an intramuscular injection of 555 kBq 54Mn. Four groups of six birds each were fed, one bird per cage, diets containing 2.8, 9.1, 25.8, and 59.7 ppm Mn for 16 days before slaughter and carcass analyses. Two groups of 7 birds were fed the diets with 9.1 and 25.8 ppm Mn for 8 days. Mn supply significantly affected 54Mn excretion and its distribution among various body organs, especially the liver. The specific activity of Mn in excreta and in whole-body declined exponentially with time and differed between groups. Endogenous Mn in excreta was estimated on the basis that the specific activity of excreta Mn from day 9 to 12 and day 13 to 16 was reflected, on the average, by that of liver Mn on day 10 and 14, respectively. It averaged in the order of increasing Mn supply 12.5 vs. 12.0; 7.7 vs. 8.5; 3.9 vs 4.3, and 2.0 vs 2.3% of total excreta Mn. Total Mn excretion from day 9 to 16 averaged 88.9, 95.0, 97.9, and 98.9% of Mn intake.

Animals↗

PubMed1988

[Amino acid pattern in the bodies and several organs of broilers fed different provisions with tryptophan and neutral amino acids].

Carcasses and organs of 36 broiler chicks originating from an extensive fattening experiment with differing proportions of tryptophan (0.65 and 0.93 g/16 g N) to the neutral amino acids (15.2, 18.3 and 22.0 g/16 g N) in feed were analyzed for amino acid contents. Aside from the whole carcasses, a selected muscle (M. fibularis longus), liver, small intestine, and brain were prepared from the animals and analyzed. The organ weights differed according to the live-weights with the exception of the brain, where no group differences were measured. The patterns of amino acids of carcasses and organs remained nearly constant with differing amino acid supply. The only remarkable effect was the increase of the proportions of proline and hydroxyproline in the carcass protein from 6.4 to 7.4 and from 1.6 to 1.8%, respectively, with the higher tryptophan supply indicating increasing proportions of connective tissue. No relationship between weight gain and collagen content (calculated from hydroxyproline content) could be detected. The frequently supposed antagonism between tryptophan and the neutral amino acids, especially at the border of blood and brain, caused no reduction in tryptophan content of brain with increasing supply of neutral amino acids. There was, however, a significant depression of the development of the animals and the other inner organs.

Amino Acids↗