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D Giesecke

Publications and source records attributed to D Giesecke.

At least 19 recordsLinked to original sources
PubMed1994

Mammary and renal excretion of purine metabolites in relation to energy intake and milk yield in dairy cows.

This investigation was conducted to quantify the purine excretion of cows and to evaluate milk allantoin as an estimator of synthesis of microbial protein in the rumen. Concentrations in plasma of allantoin and uric acid and their excretion in urine and milk were determined using 16 Holstein cows at 21 to 315 d of lactation and yielding 8 to 36 kg/d of milk. The mean daily intake of a 55:45 roughage and concentrate diet was 16.3 kg of DM with 106 MJ of NEL and 13.8 to 16.0% CP. Total urine was collected over 24 h, plasma samples collected four times, and milk samples collected twice on the same day. Analyses of purine metabolites were performed with HPLC. On average, excretion of allantoin in urine and milk was about 294 and 4.1 mmol/d for allantoin and 35 and 1.1 mmol/d for uric acid. Excretion of allantoin in milk was correlated to concentration in plasma (r = .84). As milk yield increased, percentage of milk allantoin increased from .6 to 2.4% of total allantoin excretion (r = .85). The correlations of NEL intake with allantoin excretion in milk (r = .80) and in urine (r = .84) were similar. Daily milk yield was correlated with plasma allantoin (r = .78) and milk allantoin excretion (r = .95). We concluded that determination of milk allantoin is a useful, noninvasive method to monitor rumen microbial protein synthesis.

Allantoin↗
PubMed1994

[The influence of rumen metabolism on cyclic N compounds in the blood plasma of ruminants].

The purpose of this paper was to study the effect of rumen metabolism on the concentration of certain cyclic N-compounds in blood plasma. The plasma from two groups of lambs in the phase of rumen development during early and late weaning was used. As a second model, samples from steers fed at maintenance and after emptying of the rumen via cannula were used. Plasma samples were obtained from the jugular vein in regular intervals. The HPLC-technique was employed as analytical method. The plasma levels of allantoin and of hippuric acid increased about 2.2-3.7 fold and 2.4-6.4 fold in lambs during rumen development. They decreased to about 43% and 13% after emptying the rumen of steers. These metabolites appear to reflect rumen protein synthesis and fibre breakdown and are considered useful estimators of rumen function. Cytidine, uridine, uric acid and hypoxanthine were only influenced in part by rumen metabolism. Plasma pseudouridine was decreased and creatinine was increased in lambs in relation to body mass and remained unaffected in steers.

Animals↗
PubMed1993

[The postnatal development of porcine purine catabolism and the effect of the environmental temperature on turnover].

Experiments in piglets indicate that the catabolic metabolism of purines is only developed during the first 4 weeks of life. During this time the catalytic activity of uricase in liver homogenates is increased about 5.5 fold (p < 0.01). The counts of uricase-carrying peroxisomes and cores are increased to a similar degree (p < 0.01). In the same time the catalytic activity of cytosolic xanthine oxidase is elevated about 4.6 fold (p < 0.01), mainly in the second and third week. In blood plasma uric acid is decreased from 19 to 12 molar % during weeks 1 to 4, hypoxanthine, xanthine and allantoin remain relatively constant. In urine xanthine and uric acid are decreased, hypoxanthine and allantoin are increased. At the age of 2-3 days a decrease of ambient temperature from 32 to 20 degrees C caused an increase of the plasma pool (p < 0.01) and turnover (p < 0.05) of uric acid. Pool size and turnover of hypoxanthine are only slightly elevated. The results are discussed in view of the slow development of hepatic enzymes, the increase of uric acid pool at lowered ambient temperature and causal events leading to urate nephropathia.

Animals↗
PubMed1992

Postnatal development of hepatic xanthine oxidase in baby pigs and turnover of purine catabolites at reduced ambient temperature.

1. The activity of xanthine oxidase in liver samples of baby pigs up to 4 weeks of age was investigated. On the 3rd day of life the turnover of hypoxanthine and of uric acid were measured after intravenous injection of 3H- and 14C-labelled tracers into animals kept at normal (32 degrees C) and reduced (20 degrees C) ambient temperature. 2. Hepatic xanthine oxidase activity increased progressively from 2 to 28 days of age (r = 0.689; P < 0.001). The increase of Vmax and of KM within 3-4 weeks was about 4.5-fold. 3. In 3-day-old baby pigs kept at normal temperature, pool size and turnover was about 10-fold higher for hypoxanthine than for uric acid. 4. At reduced ambient temperature, the pool size of uric acid increased 3.9-fold (P < 0.01) and turnover 1.6-fold (P < 0.05). For hypoxanthine the increases were insignificant.

Animals↗
PubMed1992

[The effect of the energy intake of cows on the rumen metabolism studied using the excretion of allantoin in milk].

With two groups of dairy cows (A: 12 German Black and White- and 6 German Simmental Cows; B: 16 German Black and White- and 11 German Simmental Cows) allantoin concentrations of blood plasma (A) and milk (A and B) were analysed by HPLC. There exists a close correlation (r = 0.758) between allantoin concentration in blood plasma (370.6 +/- 79.1 mumol/l) and milk (474.1 +/- 78.9 mumol/l). The relation between milk yield and allantoin excretion with milk seems to be non-linear (r = 0.936). On the other hand there is a close correlation between energy intake with feed and allantoin excretion via milk (r = 0.885). In a further experiment the allantoin concentrations in blood plasma of 5 Angler steers were monitored for 24 h every second hour with feeding twice daily. There were remarkable fluctuations in the allantoin concentration from nearly 156 to 129 mumol/l. After that the rumen of the steers was emptied, while plasma concentrations were still monitored the same way as before. Concentrations of allantoin declined for about 55% to 65 mumol/l.

Allantoin↗
PubMed1991

[Purine and pyrimidine metabolites for the estimation of rumen metabolism: HPLC analysis in milk and blood plasma].

In milk and blood plasma samples of 6 German Simmental and 12 German Black and White heifers it was investigated, whether purine and pyrimidine compounds are suitable indicators of the microbial protein synthesis in the rumen. Therefore the secreted quantities in milk and the concentration in blood plasma are correlated with energy intake. The results indicated significant correlation coefficients for both the secretion quantity of allantoin in milk (r = 0.942) and the concentration of allantoin in blood plasma (r = 0.694). Other investigated compounds appeared more suitable for evaluating the mammary gland metabolism (uridine-lactose synthesis, pseudouridine-protein synthesis). In an experiment with 7 male castrated pigmy goats subjected to a four-day fasting period the decrease of plasma allantoin, which was already apparent after 12 hours of fasting, was closely correlated with the increase of plasma free fatty acids.

Allantoin↗
PubMed1990

[Effects of purine-rich nutrition on the renal and extrarenal excretion of purine catabolites in Dalmatian dogs].

In eight Dalmatian dogs exogenous effects (dietary purine, xylit infusion) on plasma uric acid were examined and relationships between purine intake and excretion were established. Increasing purine intake resulted in a linear increase in renal excretion of urate (r = 0.952) and a less steep increase of allantoin (r = 0.901). In pairs of two animals with low and high purine intakes the metabolic fluxes in steady state were measured by continuous infusion of (2-14C) urate. The extrarenal excretion rates of urate + allantoin during high-purine and low purine feeding averaged 2.9% and 8.5% of entry rates. The results are discussed in comparison with human data and a remarkably good agreement is observed.

Allantoin↗
PubMed1990

[Effect of purine-rich nutrients on weight gain, catabolites in blood plasma and the uric acid transport of erythrocytes--a model study in dogs].

In a nutritional tolerance study 36 young dogs were fed over 52 weeks high or low purine diets at an average paired feeding intake of 0.6 and 80 mg purine-N/MJ per day. The high purine diet resulted in a significant decrease of growth rate by -23% (Beagles) and -38% (Dalmatians) and of feed efficiency (-29 and -42%). The fasting levels of allantoin, uric acid and uracil in blood plasma were significantly increased. During the experiment a metabolic adaptation to the high purine diet decreased the plasma concentrations of uric acid, uracil and in part of allantoin. The high purine diet effected a significant increase of Km (2.5-fold) and of Vmax (1.6-fold) of uric transport through the erythrocyte membrane. The results documented disadvantageous effects of high purine nutrition during juvenile development.

Allantoin↗
PubMed1990

[The effect of glucocorticoid on the glucose metabolism of pigmy goats. 1. Selected metabolites of energy metabolism].

In order to study mechanisms in ruminants responsible for glucocorticoid-induced hyperglycemia the effects of a single intravenous dose of a glucocorticoid on energy metabolism were investigated by measuring plasma levels of glucose, lactate, free fatty acids (FFA), 3-hydroxybutyrate (3-HOB) and acetoacetate (AcAc). Experiments were performed on four castrated male African pygmy goats at two metabolic states: "fed" with a single daily meal of hey and "fasted" with starvation for 3 days. The untreated goats served as their own control. The glucocorticoid application to fed animals resulted in an increase in glucose level (+43%) lasting more than 11 h and an irregular increase of lactate. The concentration of 3-HOB was increased especially before feeding (+64%). In contrast, FFA were decreased (-27%) the second day after glucocorticoid application. In fasted goats the glucocorticoid also caused an increase in glucose level (+25%). The effect was smaller than in fed animals. Concentrations of FFA, 3-HOB and AcAc were 10, 20 and 35% lower than those of untreated goats. With regard to the antiketotic use of glucocorticoids the decrease of plasma levels of FFA and ketone bodies in starving animals is of special importance. Obviously the animals were able to use glucose again as a main energy source instead of FFA.

3-Hydroxybutyric Acid↗
PubMed1990

[Electron microscopic morphometric studies of the development of peroxisomes in healthy piglets during the first 4 weeks of life].

The number of hepatic peroxisomes, cores, marginal plates, and microperoxisomes in piglets increases from a low level at birth, compared with other species e.g. the rat, to day 28 of life. The number of peroxisomes is correlated to the activity of uricase, but morphometry alone is not sufficient to quantitate uricase activity. These findings might explain the occurrence of renal uric acid deposition (infarction) during a catabolic state, where body protein is metabolized to an increased extent and purine levels rise. Due to a relative lack of uricase uric acid is not completely oxidised to allantoin.

Animals↗
PubMed1989

Quantification and kinetics of purine catabolism in Dalmatian dogs at low and high purine intakes.

1. In eight Dalmatian dogs low and high purine intakes resulted in plasma urate levels from 25 to 185 mumol/l. 2. The relationship between purine intake and excretion of uric acid and allantoin per day was described by linear regression equations. 3. The elimination of endogenous purines was 1.8 mmol/day for urate and 1.7 mmol/day for allantoin. Exogenous purines increased renal excretion by 0.57 mmol/mmol. 4. Kinetic measurements with [2(-14)C]uric acid infused continuously into each of two dogs on low and high purine revealed increases of plasma pool (urate + allantoin) of 3.3 fold and entry rate of 4.0 fold. Conversion of urate into allantoin increased from 20 to 36%. 5. Renal elimination of catabolites increased 3.3 fold and exhalation rate of purine-CO2 379 fold. Extra-renal elimination at high purine intake was quantitatively similar to humans and closely related to pool size.

Allantoin↗
PubMed1987

Postnatal development of hepatic uricase and peroxisomes in baby pigs.

1. The activity of uricase, the densities of peroxisomes and cores in liver samples of baby pigs up to 4 weeks of age were investigated. 2. From 1 to 4 weeks of age, uricase activity as well as counts of cores and peroxisomes increased 5.5-, 3.3- and 2-fold. 3. Uricase activity and counts of cores and peroxisomes were correlated (P less than 0.001) with age in linear relationships. 4. Calculated for time of birth uricase activity was very low and ratio of cores to peroxisomes was 1:7. 5. From 0 to 28 days of age the calculated increases of uricase activity and counts of cores and peroxisomes were 178-, 10- and 3-fold.

Aging↗
PubMed1986

[Serum magnesium concentration in myocardial infarct].

Serum magnesium concentrations were followed during the course of coronary infarction and were correlated to the event on the basis of the creatinine kinase activity E.C. no. 2.7.3.2. Those patients admitted to the hospital at a very early stage of the infarction showed initial high serum magnesium concentrations which fell during the event to subnormal values and then normalized later. In the case of severe coronary infarction (maximum CK activity greater than 700 U/1) the subsequent decrease in serum magnesium concentration was more pronounced than in subjects with lower CK activity. Patients suffering from angina pectoris had normal serum magnesium values which did not show any concentration change during a clinical follow-up. The previously postulated correlation between low serum magnesium and high risk for myocardial infarction may be questioned in the light of our observations.

Aged↗
PubMed1986

Uric acid uptake in erythrocytes of beagle and dalmatian dogs.

Uric acid uptake by erythrocytes of Beagle and Dalmatian dogs has been measured, using (2-14C) uric acid. Uptake was characterized by a fast and a slow component. Urate uptake was inhibited by certain purine and pyrimidine derivatives and by anion transport inhibitors. It was dependent on intraerythrocyte glycolysis. Temperature only influenced uptake by the slow component (Q10 = 2.6). Urate uptake by the slow component is apparently due to the transport into the erythrocytes by facilitated diffusion (Km = 6.6 mmol/l, Vmax = 390 mumol/l/min), whereas the fast component exhibits an adsorption of urate on erythrocyte surface. No difference of urate uptake by erythrocytes of Beagle and Dalmatian dogs has been observed.

Animals↗
PubMed1986

The role of adipose and hepatic tissues in the lipogenesis of the dog.

In order to determine the main organ of fatty acid synthesis de novo in the dog, glucose-C incorporation into fatty acids and glucose-1-C oxidation to CO2 were measured by means of glucose-U-14C and glucose-1-14C in samples of adipose and hepatic tissues of 16 animals. For comparison of the two organs the data were referred to the respective DNA content. The rate of glucose-C incorporation into fatty acids of adipose tissue exceeded that of hepatic tissue about 1000-fold. Therefore, the adipose tissue is to be considered the almost exclusive organ of lipogenesis in the adult dog. Glucose-1-C oxidation and glucose-C incorporation in adipose tissue were correlated by r = 0.887. Consequences of these results may be of concern in model experiments using dogs.

Adipose Tissue↗
PubMed1985

[D(-)Lactic acid--a metabolism problem].

The metabolization of D-lactate was examined in volunteers by means of renal excretion after intake of DL-lactate, and in rats as well as in rat liver in vitro by the oxidation rate of 14C-D-lactate to 14CO2. In five volunteers after intake of DL-lactate containing 1.60 to 6.5 mmol D-lactate per kg 0.75 (equiv. to 50-200 mg/kg) an average of 1.2-2.2 percent of the dose was eliminated in urine. The exponential decline of renal elimination during the first 15 hours after intake and the total excretion time up to 24 hours (and possibly more) suggested a quite slow rate of metabolism. Following intraperitoneal injection of 2.0 and 4.2 mmol per kg 0.75 in rats (equiv. to 62 and 131 mg per kg in man) the oxidation rate of D-lactate vs. L-lactate was significantly and strongly reduced. After intragastral dosage of DL-lactate containing 4.2 to 12.8 mmol D-lactate per kg 0.75 an average of 0.9 and 2.4 percent were excreted in urine as D-lactate and as metabolites. Even after the lowest dose D-lactate oxidation to CO2 extended far beyond 8 hours. Higher doses decreased the rate of D-lactate oxidation. In tissue samples of rat liver in vitro oxalate, L-lactate and pyruvate inhibited the oxidation of D-lactate. L-lactate in a physiological concentration was sufficient to effect an inhibition of 20 percent. A significant increase of D-lactate oxidation with increasing body weight and a significantly higher oxidation of D-lactate in conventionals vs. germ-free rats indicated the influences of age and gastro-intestinal flora on D-lactate metabolism. From these results it is concluded that D-lactic acid is only slowly metabolized if the concentration of one or other of the lactate isomers is elevated.

Adult↗