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PubMed2005

Effects of postexercise supplementation of chicken essence on the elimination of exercise-induced plasma lactate and ammonia.

We investigated the effects of chicken essence (CE) supplementation on exercise-induced changes of lactate and ammonia during recovery. In this randomized, double blind, crossover study, twelve healthy subjects performed a single bout of exercise to exhaustion, and then consumed either a placebo or CE within 5-min of the exercise cessation. Blood samples were collected before exercise, at exhaustion (0 minute), and 20, 40, 60, and 120 minutes, respectively during the recovery period. There were no differences in plasma glucose, creatine kinase, or heart rate responses between treatments. The exercise exhaustion significantly increased the levels of lactate and ammonia, and both measured values gradually declined during the recovery period. Ammonia levels at 40, 60, and 120 min. of the recovery period were observed lower significantly in the CE group, as compared to those in the placebo group. Additionally, lactate concentrations at 60 and 120 min were lower in the CE group, as compared to those in the placebo group. In conclusion, the main finding of this study was that CE supplementation after exercise reduces plasma lactate and ammonia levels. The results indicated that CE supplementation after an exhaustive exercise could enhance physiological recovery in humans.

Adult↗
PubMed1991

Effects of acute hepatic encephalopathy and in vitro treatment with ammonia on glutamate oxidation in bulk-isolated astrocytes and mitochondria of the rat brain.

The metabolism of [1-14C] glutamate to 14CO2 and the glutamate dehydrogenase (GLDH) activity towards alpha-ketoglutarate (alpha-KG) formation were measured in bulk isolated astrocytes derived from control rats and rats with acute hepatic encephalopathy (HE) induced with thioacetamide. In addition, the effects of in vitro treatment of control and HE astrocytes and non-synaptic mitochondria with toxic (3mM) NH4Cl concentration were followed. [1-14C] glutamate oxidation measured as a whole was identical in control and HE astrocytes and was inhibited by ammonia to the same degree in either fraction. In the presence of a glutamate transamination inhibitor--3mM aminooxyacetic acid (AOA), when only the GLDH-mediated part (25% of total) of the glutamate oxidation remained active, the inhibitory effect of ammonia treatment was much more pronounced in HE astrocytes than in control astrocytes. The ability of non-synaptic mitochondria to utilize glutamate to CO2 was not changed in presence of 3mM NH4Cl, whereas a substantial decrease of CO2 production (about 80%) in both the control and HE preparations was observed in the presence of 3mM AOA. GLDH activity was not at all affected by either of the experimental conditions, both in astrocytes and purified non-synaptic mitochondria. Thus, the inhibition of glutamate oxidation in astrocytes by ammonia and the compounded inhibitory effect of HE, ammonia and AOA appeared to be located beyond the glutamate dehydrogenation step within the tricarboxylic acid cycle.

Ammonia↗
PubMed2006

[Enhanced ammonia removal and microbial community structure analysis using bacterial quinone profile in ITFB].

Water quality during the start-up period was changed in order to enhance the later nitrifying ability of the internal-circulation three-phase bio-fluidized bed (ITFB). The experimental results showed that high N/C ratio and low feeding concentration of COD were two key conditions for enhancing the ammonia removal. After the enhanced start-up, an efficient removal efficiency of both COD and ammonia was achieved with HRT 2h when treating sanitary wastewater, the average ammonia removal rate was 74% , the ammonia concentration in effluent was lower than 10 mg/L. Bacterial quinone profile of the system was also analyzed. The results showed that after the enhanced start-up, the number of nitrifying bacteria, such as Nitrosomonas europaea, in the biofilm in ITFB was increased, and the number of gamma-Proteobacteria, such as Acinetobacter sp. and Pseudomonas sp., was decreased. the equitability of the quinones (EQ) fluctuated around 0.5 showed that the distribution of the microbial community in the biofilm changed little. UQ/MK ratio of all the samples was greater than 1 indicated that Gram-negative bacteria was the dominant bacteria in the system.

Ammonia↗
PubMed1991

Noninvasive quantification of hepatic arterial blood flow with nitrogen-13-ammonia and dynamic positron emission tomography.

To determine if dynamic PET and 13N-ammonia can be utilized to quantitate regional hepatic arterial blood flow (rHABF) noninvasively, eight anesthetized dogs and eight human volunteers were examined with PET following intravenous bolus administration of 13N-ammonia. Hepatic time-activity curves and the arterial input function were derived from ROIs drawn over the right lateral superior segment of the liver and the left ventricle of the heart, respectively. rHABF was quantitated using a two-compartment model, with comparison with simultaneously acquired microsphere blood flow measurement (MS) in the canine studies. rHABF derived from canine dynamic PET with 13N-ammonia were linearly related to microsphere values (rHABF = 0.92 x MS + 0.04, r = 0.98), with a mean of 0.40 ml/min/g. The results in eight normal volunteers gave a rHABF value of 0.26 +/- 0.07 ml/min/g. Dynamic 13N-ammonia hepatic PET allows noninvasive quantification of rHABF.

Adult↗
PubMed1991

Cage ammonia levels during murine reproduction.

Monogamous pairs of inbred BALB/c and outbred CD-1 mice housed in M2 cages with a floor area of 330 cm2, produced a mean cage ammonia level of 26 ppm and 154 ppm respectively over a four day period prior to weaning their litters. A gradient of ammonia exists from the nest to the food hopper. By housing CD-1 monogamous pairs in RM2 cages which have double the floor area of M2 cages (676 cm2), a lower mean level of ammonia was recorded at the same stage of reproduction and air sampling. The CD-1 mice in particular, were subjected to high levels of ammonia when compared with long term human health and safety occupational exposure limits of 25 ppm.

Ammonia↗
PubMed1991

The effect of metabolic milieu on cardiac PET imaging using fluorine-18-deoxyglucose and nitrogen-13-ammonia in normal volunteers.

Cardiac PET imaging using 13N-ammonia and 18FDG was performed on 17 normal volunteers in the glucose-loaded and fasted states. PET images (glucose-loaded and fasted) were subjected to qualitative visual analysis using the descriptors: image quality, FDG blood-pool activity, ammonia lung field activity, and clinical interpretability. Glucose-loaded studies had better image quality, diminished FDG blood-pool activity, and were more often clinically interpretable compared to fasted studies. Dietary state did not affect 13N-ammonia study parameters. Using a semi-quantitative region of interest method, 18FDG myocardial activity was homogeneous and significantly affected by dietary state (2.48 +/- 1.0 fold increase in myocardial-to-blood pool ratio in glucose-loaded versus fasted states). Serum glucose, insulin, and free-fatty acid concentrations responded physiologically to glucose loading and fasting but showed no correlation with myocardial 18FDG uptake. PET imaging using 13N-ammonia and 18FDG appears optimal in the glucose-loaded state.

Adult↗
PubMed1990

[Incidence of pathologic ammonia concentrations in the plasma in children with seizure disorders treated with Convulsofin/Convulex and other anticonvulsants in comparison with children with brain damage and healthy children].

In healthy children plasma ammonia concentrations show values from 12.3 to 57.2 mumol/l (80%-range) (group I). We also measured plasma ammonia in epilepsy patients with valproate therapy (group II) and epilepsy patients treated with other anticonvulsiva (group III). In a fourth group there were children with various cerebral lesions without episodes and without anticonvulsiva therapy. There were significant differences between group I and group II and group II and group IV respectively. But no significant differences were found between the patients who were treated with valproate and the patients with cerebral lesions. The data does not allow the plasma ammonia concentration to be taken as a control parameter in children treated with valproate. Ammonia estimation at the beginning of therapy, however, may be used as risk indicator.

Adolescent↗
PubMed1990

Comparison of colourimetric methods for ammonia determination.

The precision of the Berthelot and Nessler methods of ammonia determination are compared at various ammonia concentrations. Recommendations are made regarding the most appropriate technique to use, dependent on the range of ammonia concentration expected. The effect of microdiffusion separation on the precision of ammonia determination is studied, together with an evaluation of a water soluble lid sealant and of the effect of a model amine contaminant.

Ammonia↗
PubMed1990

Preanalytical increase of ammonia in blood specimens from healthy subjects.

The course and magnitude of spontaneous increase in ammonia concentration in plasma on standing were investigated with EDTA-treated blood specimens from 36 healthy subjects with use of a sensitive and precise enzymic method. Over 90 min, the rates of increase were virtually constant at fixed temperature. The mean (and SE) rates at 0, 20, and 37 degrees C were 3.9 (0.23), 5.2 (0.23), and 25.2 (0.59) mumol/L per hour, respectively. At these temperatures, the plasma contributed at most 7%, 15%, and 10%, respectively, to the formation of ammonia in whole blood. In view of the medical needs and the measured rates of ammonia increase, an interval of 15 min between blood sampling and the start of centrifugation may be tolerated at a specimen temperature of 0 degree C. Rates of ammonia increase showed significant correlations with erythrocyte and platelet count as well as with the plasma activities of gamma-glutamyltransferase (EC 2.3.2.2) and alanine aminotransferase (EC 2.6.1.2).

Adolescent↗
PubMedDate not supplied

[Ammonia content of the brain, liver and blood of rats in radiation injury].

The neuroparalytic syndrome induced by ammonia was compared with the X-radiation-induced cerebral syndrome. It is suggested that the accumulation of ammonia in the brain and liver of rats is one of the reasons for the similarity of the studied syndromes. The fact that ammonia is bound by glutamic acid indicates that the latter is involved in the mechanisms of ammonia utilization and in the radioprotective properties manifestation.

Ammonia↗
PubMed1986

[Postprandial exchange of urea and ammonia nitrogen between the digestive tract and portal blood in the conscious pig after ingestion of a diet with or without urea].

The concentrations of urea and ammonia were measured in the portal and arterial blood simultaneously to the blood flow rate in the portal vein during the postprandial period (8 hrs.) after ingestion of a normal protein diet with 3% urea (10 meals) or without urea (12 meals) in conscious pigs (mean body weight: 55.5 +/- 2.3 kg). When no urea was present in the diet, there was a slight and permanent uptake of blood urea by the gut (570 mg/h, i.e. 9,5 mmoles/h) as well as a permanent appearance of ammonia in the portal vein (258 mg/h i.e. 15.2 mmoles/h), increasing with time (P less than 0.05). The absorbed ammonia nitrogen represented a maximum of 70% of urea nitrogen taken up. 2. Addition of urea to the diet brought about a large absorption of that substance (73% of the ingested amount) followed by a rather large excretion (960 mg/h, i.e. 16 mmoles/h), 5-6 hrs. after the meal and led to an increase (P less than 0.05) in the absorption of ammonia.

Ammonia↗
PubMed1988

[Dynamics of ammonia levels during long-term storage of canned meats].

Ammonia content in relation with sensory changes was studied in four kinds of meat cans (Pork in Natural Juice, Beef with Bacon, Luncheon Meat, and Liver Pâté), stored for 36 months under constant conditions (average temperature 21 degrees C. average relative humidity 73%). Four groups of final products were prepared from each kind of these cans; the final products differed from one another in the ammonia contents, depending on the freshness of the food. After sterilization and cooling, i.e. after the termination of the technological process of production, the produced meat cans were subjected to sensory evaluation and their ammonia contents were determined. These values were used as initial data for the start of long-term storage. In the course of long-term storage the selected parameters were measured in regular intervals. It was concluded from the experimental results that the content of ammonia slightly increased with the time of storage of the tested kinds of meat cans without any significant influence on their sensory characteristics that would affect their use for human consumption.

Ammonia↗
PubMed1987

Whole-body protein turnover in man determined in three hours with oral or intravenous 15N-glycine and enrichment in urinary ammonia.

Studies were carried out in eight normal adults to simplify the continuous infusion-end product method for measuring whole-body protein turnover using 15N-glycine. When a priming dose of label suitable for the urea pool was followed by intermittent oral doses of label, plateau enrichment was maintained in urinary urea and ammonia from 9 to 18 h, giving values for nitrogen flux (18 h) of 0.69 +/- 0.05 g N/kg/d with urea and 0.46 +/- 0.01 g N/kg/d with ammonia. With a priming dose appropriate for the ammonia pool, plateau was reached in urinary ammonia in less than 120 min and maintained for up to 6 h. Nitrogen flux (3 h) with oral 15N-glycine was 0.96 +/- 0.12 g N/kg/d, and with intravenous label was 0.61 +/- 0.13 g N/kg/d. There was a significant linear relationship between flux measured with oral and intravenous isotope. It is suggested that different components of protein turnover are measured with the different approaches, and that the short method in particular measures rapidly turning over proteins associated with the gastrointestinal tract.

Adult↗
PubMed1985

[Myocardial positron computed tomography using N-13 ammonia for evaluating coronary artery disease: comparison with thallium-201 emission computed tomography].

To assess myocardial perfusion in patients with coronary artery disease (CAD), N-13 ammonia positron computed tomography (PCT) was performed for 32 cases, and the PCT images were compared with those of single-photon emission computed tomography (SPECT) using thallium-201. Myocardial perfusion images were obtained with a whole-body multislice PCT device following the intravenous injection of 10 to 20 mCi N-13 ammonia at rest (32 cases) and during exercise (23 cases). Eleven cases underwent serial 15-20 second dynamic studies immediately following the N-13 ammonia injection. Serial dynamic study showed the blood-pool images in the first scan, and enabled assessment of tracer washout from the blood-pool, and the lung as well as washin into the myocardium. PCT provided clear resting myocardial perfusion images in all cases. PCT images were of higher quality than those of SPECT due to higher spatial resolution with less statistical noise, allowing delineation of the right ventricular myocardium and papillary muscles in many cases. Both PCT and SPECT detected perfusion abnormalities in 18 of the 19 cases with myocardial infarction, without false positive findings. PCT yielded stress myocardial images and permitted comparative evaluations of myocardial perfusions at rest and during exercise in all 23 cases. Perfusion abnormalities were detected in 14 cases (74%) at rest and in 18 cases (95%) during exercise among 19 patients with CAD. No false positives were observed, either by resting or stress PCT imaging. Stress myocardial PCT identified regional perfusion abnormalities in 30 of the 34 regions supplied by stenosed vessels (88%). High resolution PCT images enabled precise evaluation of myocardial perfusions which proved valuable for assessing myocardial perfusions before and after aorto-coronary bypass surgery. The present study proved advantages of N-13 ammonia PCT in creating three-dimensional high resolution images of the myocardium, which facilitates precise evaluation of myocardial perfusions. Furthermore, its potential capabilities in quantifying coronary reserve function will be very useful. This method should provide valuable pathophysiological information for CAD, as well as for metabolic PCT imaging.

Ammonia↗
PubMed1985

Ammonia movements in rhizobia.

When free-living rhizobia are grown under N-excess conditions they appear to take up ammonia by a diffusive mechanism. Under low or limiting N, they derepress an ammonium permease which serves to scavenge NH4+. Current data suggest that N2-fixing bacteroids lose ammonia by a diffusive movement sustained by the continual removal of ammonia via the plant ammonia assimilatory system(s).

Ammonia↗
PubMed1986

Effects of storage temperature and time on canine plasma ammonia concentrations.

Stability of ammonia in canine plasma was determined, with regard to temperature and time of storage. Heparinized venous blood samples were collected from 8 healthy dogs, immediately placed in an ice water bath, and centrifuged at 5 C. Plasma was harvested from the blood samples, and the initial analysis of each sample for plasma ammonia was performed within 30 minutes after collection. Separate aliquots of the plasma from each dog were stored at 21 C, 4 C, -15 C, or -40 C. Ammonia concentrations of the aliquots stored at the various temperatures were determined at 24, 48, and 96 hours after collection. Statistical analysis of the data from each dog did not indicate a significant relationship between the initial concentration of plasma ammonia and subsequent determinations. Correlation or significance was not found among samples stored at similar temperatures and evaluated at similar times.

Ammonia↗
PubMed1985

Relationship of phosphate-dependent glutaminase activity to ammonia excretion in potassium deficiency and acidosis.

Ammonia production and excretion are elevated in potassium depletion alkalosis, although normally they are reduced in alkalosis and elevated in acidosis. Studies were conducted with or without acute acid loading in normokalemic rats or rats made chronically hypokalemic with deoxycorticosterone acetate and a potassium-deficient diet to examine the role of phosphate-dependent glutaminase (PDG) in regulating ammonia excretion. Renal cortical PDG rose fourfold, and urinary ammonia excretion (UAE) doubled in potassium depletion compared to potassium-repleted controls. Following acid challenge PDG and urinary ammonia increased four- to sevenfold in both normokalemic and hypokalemic animals, but the rise in UAE did not correspond to the increase in PDG. Thus, PDG levels in acidotic normokalemic rats were one half those seen in potassium-depleted rats, but UAE in the acidotic rats was six times greater. These results could not be explained solely by changes in blood pH. The poor correlation between PDG and UAE also could not be explained by limited substrate availability, since blood glutamine levels were unaffected by potassium depletion. The disparity between UAE and PDG in potassium depletion was studied further during 9 days of potassium repletion of depleted rats. UAE was again increased by depletion but, after only 3 days of potassium repletion, UAE fell to levels found in normokalemic rats. The renal PDG activity, however, remained three times normal. Indeed, PDG remained significantly elevated even after 9 days of potassium replacement. Other enzymes involved in renal ammoniagenesis, including delta glutamyl transferase, glutamine transferase and omega deamidase, were assayed, and alterations in their activities could not account for the changes in UAE.(ABSTRACT TRUNCATED AT 250 WORDS)

Acidosis↗
PubMed1985

Ektachem multilayer dry-film assay for ammonia evaluated.

We evaluated the Kodak Ektachem multilayer dry-film method for ammonia. Within-day precision (CV) was 5.9% and 2.7% at ammonia concentrations of 53 and 654 mumol/L, respectively. Between-run precision (CV) was 7.8% and 7.3% at 51 and 109 mumol/L, respectively. Correlation with a manual ion-exchange chromatography-Berthelot reaction-based method (x) was good (y = 0.96x - 1.37; r = 0.984; SEE = 9.16). The response of the method varies linearly with ammonia concentration up to 900 mumol/L. Bilirubin less than or equal to 270 mg/L, triglycerides less than or equal to 6.0 g/L, and slight hemolysis did not interfere. The concentration of ammonia in plasma of 120 healthy adults was 16-53 mumol/L (nonparametric central 95 percentiles).

Ammonia↗