Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0002063 (alkalosis)
 2,286 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The purpose of the study was differential diagnosis of lactic acidosis in 44 children aged from 2 weeks to 4 years. In all of them the lactate level in repeated determinations exceeded 27 mg/100 ml. From the point of view of clinical manifestations the children were divided into three groups: 26 with hepatomegaly and hypoglycaemia (I), 6 with ataxia and retardation of somatic development (II), 12 with mental retardation and muscular hypotonia (III). Together with basic biochemical studies other tests were done, if necessary, including glucose and alanine loading, lactate determination in cerebrospinal fluid, analysis of urinary organic acids by the GC-MS method, morphological examinations of muscle biopsy material, enzymatic determinations in liver biopsy material. In group I glycogenosis was suspected and its type was finally established after biochemical and enzymatic tests (types I, Ib, III, VI, VIa, XI). In one case fructose-1,6-diphosphatase deficiency was suspected. In group II the clinical manifestations resembled Leigh's syndrome. The tests demonstrated an inhibition of glucose formation from alanine, and lactate level in the cerebrospinal fluid was evidently raised above that in the serum. Gasometric index showed the presence of respiratory alkalosis with metabolic compensation rather than primary lactate acidosis. In group III, with considerable clinical variety of signs, in only nine out of 12 children the cause of lactate acidosis could have been established (pathological changes of mitochondria in 4 cases, secondary increase of lactate without pathogenetic importance in 4, and 3-hydroxy-3-methylglutaric acidosis in 1 case. In conclusion it is thought that this combination of diagnostic methods is useful in differential diagnosis of congenital lactate acidosis in children.
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PMID:Congenital lactic acidosis in children--differential diagnosis in 44 cases. 184 18

The relative significance of the flux through the glutamine aminotransferase (glutaminase II) pathway to renal ammoniagenesis is poorly understood. A basic and unresolved question is whether 2-oxoglutaramate (2-OGM), a product of the glutaminase II reaction, is deamidated to yield 2-oxoglutarate and NH3, or whether 2-OGM accumulates as an unreactive lactam, depending on the environmental pH. In the current studies we utilized 13C n.m.r. as well as 15N n.m.r. as well as 15N n.m.r. to demonstrate that 2-OGM occurs as a lactam, i.e. 5-hydroxypyroglutamate, regardless of the environmental pH. Our additional aims were to determine whether human kidney cells (HK cells) in culture can produce 2-OGM and to ascertain a pH-dependent relationship between NH3 and 2-OGM production from glutamine. We therefore developed an isotope dilution assay for 2-OGM utilizing 5-hydroxy[4-13C,1-15N]pyroglutamate as the labelled species. Incubations of HK cells in minimal essential medium supplemented with 1 mM-[2-15N]glutamine demonstrated significantly higher production of 2-OGM at pH 6.8 and lower production at pH 7.6 compared with pH 7.4. Similarly both 15NH3 and [15N]alanine formation were significantly higher in acute acidosis (pH 6.8) and lower in acute alkalosis (pH 7.6) compared with that at physiological pH. Addition of 1 mM-amino-oxyacetate to the incubation medium at pH 7.4 significantly diminished [15N]alanine and 2-OGM production, but the production of 15NH3 via the glutamate dehydrogenase pathway was significantly stimulated. The current observations indicate that the glutaminase II pathway plays a minor role and that flux through glutamate dehydrogenase is the predominant site for regulation of ammoniagenesis in human kidney.
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PMID:Analysis and physiological implications of renal 2-oxoglutaramate metabolism. 185 45

The effect of metabolic alkalosis was studied in 10 healthy volunteers. In each person urea synthesis was determined in two periods of 2 h as urinary excretion corrected for accumulation in body water and for intestinal hydrolysis. Infusion of bicarbonate (115 mmol/h) increased pH of the venous blood by 0.10 units. In four subjects fasting urea synthesis was 24 mmol N/h at normal pH and unaffected by alkalosis (mean difference +/- SED was 1.04 +/- 4.1). In six subjects alanine was infused so as to increase blood alanine concentration from 0.4 to 2.5 mmol/l and urea synthesis to 107 mmol N/h. Alkalosis did not change urea synthesis (mean difference +/- SED was 1.5 +/- 7.4 mmol N/h). The results favour the view that urea synthesis mainly serves to eliminate nitrogen, but do not support the hypothesis that urea synthesis is an important immediate and direct regulatory process in acute acid-base disturbances.
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PMID:No effect of bicarbonate-induced alkalosis on urea synthesis in normal man. 216 Jan 22

A boy aged 1.5 year with deficient weight and height, retardation of motor development, decreased muscle tonus, finger tremor and periodic tachypnoea without detectable respiratory system changes is presented. Gasometry demonstrated metabolic acidosis with respiratory alkalosis, high concentration of lactic acid in serum and cerebrospinal fluid, increasing metabolic acidosis after glucose load, and lack of hyperglycaemic response after alanine load, and cortical atrophy in CT. On the basis of these changes Leigh's disease was diagnosed.
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PMID:[Leigh disease in a 17-year-old boy]. 227 48

Previous studies from our laboratory have confirmed that cultures of LLC-PK1 cells exhibit pH-responsive alterations in ammonia metabolism produced by changes in media bicarbonate concentration. To further elucidate the mechanism of ammonia regulation, studies were carried out using parallel cultures of still and rocked LLC-PK1 cells subjected to acute alterations in media pH by either metabolic or respiratory acid-base manipulations. When media pH was altered by modifying PCO2 levels, the response of ammonia and alanine production by rocked culture was identical to the changes observed with metabolic acid-base maneuvers. Furthermore, both metabolic and respiratory acute acidosis resulted in a fall of intracellular alpha-ketoglutarate concentrations in these cells. In contrast, standard still cultures subjected to acute acidosis/alkalosis by metabolic and respiratory manipulations did not exert any significant change in ammonia and alanine production or in intracellular alpha-ketoglutarate concentration. Measurements of intracellular pH (pHi) by the 5,5-[2-14C]dimethyloxazolidine-2,4-dione method in rocked cells demonstrated changes in pHi parallel to media pH changes induced by both metabolic and respiratory acid-base maneuvers. Despite the absence of pH-responsive ammonia-genesis in still cultured cells the pHi values were altered in a fashion similar to their rocked counterparts, indicating the lack of an effect of the pHi signal on ammonia metabolism.
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PMID:Relationship between intracellular pH and ammonia metabolism in LLC-PK1 cells. 240 8

In order to explore the sensitivity of spatially resolved 1H and 31P NMR spectroscopy on a whole-body NMR instrument, cerebral metabolic changes in human volunteers were measured during hyperventilation provocation. During hyperventilation the flow velocity in the middle cerebral artery decreased significantly and the EEG showed a marked increase in slow activity. 1H NMR spectra revealed an increase in cerebral lactate concentration. 31P NMR spectra showed no changes in ATP or PCr peak heights, but a shift toward tissue alkalosis was derived from changes in Pi chemical shift. During subsequent recovery, lactate concentration decreased and a slight intracellular acidosis was detected. In three experiments broadening of the lactate resonance peak resulted in separation into two components at 1.32 and 1.48 ppm, in which the latter signal possibly arose from alanine.
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PMID:1H and 31P NMR measurement of cerebral lactate, high-energy phosphate levels, and pH in humans during voluntary hyperventilation: associated EEG, capnographic, and Doppler findings. 250 71

The effects of acid-base balance disturbances on pulmonary endothelial angiotensin-converting enzyme (ACE) were studied in anesthetized mechanically ventilated rabbits. Enzyme function was estimated from [3H]benzoyl-Phe-Ala-Pro ([3H]BPAP) utilization under first-order reaction conditions during a single transpulmonary passage and expressed as 1) substrate metabolism (M), 2) Amax/Km (Amax being equal to the product of enzyme mass and the constant of product formation), and 3) (Amax/Km)/100 ml blood flow. When respiratory acidosis/alkalosis was produced by altering respiratory rate at constant airway pressure, substrate (BPAP) utilization varied proportionally to arterial pH and inversely proportionally to arterial PCO2 (PaCO2) (P less than 0.05). Percent BPAP metabolism (%M) ranged from 92 +/- 3 (respiratory alkalosis) to 85 +/- 3 (normal), 82 +/- 3 (respiratory acidosis), and 78 +/- 2% (severe respiratory acidosis). Amax/Km similarly decreased from 899 +/- 129 to 825 +/- 143, 601 +/- 74, and 450 +/- 34 ml/min, respectively, and (Amax/Km)/100 ml blood flow was reduced from 176 +/- 26 to 131 +/- 22, 111 +/- 12, and 97 +/- 5, respectively. However, when respiratory acidosis/alkalosis was produced by altering both respiratory rate and airway pressure, no changes were observed in either %M, Amax/Km or (Amax/Km)/100 ml blood flow. Similarly metabolic alkalosis or acidosis did not alter M, Amax/Km or (Amax/Km)/100 ml blood flow. These results indicate that pulmonary endothelial ACE function can be affected by acid-base disturbances, probably indirectly through changes in perfused microvascular surface area.
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PMID:Effects of acid-base imbalance on pulmonary angiotensin-converting enzyme in vivo. 282 79

Acute metabolic alkalosis was induced in dogs by the infusion of sodium bicarbonate, 0.3 M. Chronic alkalosis was induced by chloride restriction and the administration of sodium bicarbonate and furosemide. In a third group of dogs, potassium was added to the regimen to prevent frank potassium depletion. Plasma bicarbonate ranged from 29.0 to 32.9 mM. In all three dog groups, renal ammoniagenesis fell by over 30%, which was consistent with a decrease in the renal uptake of glutamine. Glutamate was released in the renal vein and alanine production was decreased. Total production of ammonia was lowest in the animals given a potassium supplement where muscle potassium decreased much less than in the other chronic animals. Urinary ammonia excretion was very low in all three animal groups; this was related to an alkaline urine. However, this relationship was not entirely consistent and the low excretion of ammonia could also be related to decreased ammonia production by the renal tubular cell. In the renal cortical tissue (freeze-clamped), the concentration of glutamate did not change and that of alpha-ketoglutarate rose only in the animals supplemented with potassium. Malate rose in all groups. In all animals, renal tissue concentration of lactate and citrate rose while citrate excretion increased. We feel that glycolysis could play an important role in renal metabolism during acute and chronic metabolic alkalosis. We have proposed a unified theory to explain the metabolic changes that occur in lactate and citrate metabolism during metabolic alkalosis with a depressing effect on ammoniagenesis. Although citrate could be generated in the mitochondria from pyruvate, its oxidation is probably inhibited with exit and accumulation in the cytosol.
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PMID:Renal tubular biochemistry during acute and chronic metabolic alkalosis in the dog. 286 5

Clinical observations and results of investigations of pyruvic acid metabolism are reported in 4 children in whom subacute necrotizing encephalomyelopathy of Leigh was diagnosed intravitally. Attention is called to the similarity of the clinical manifestations with its onset in the first year of life, deficient body weight and growth, progressing neurological disturbances (weakening of muscle power, tremor, ataxia, nystagmus), course with periods of exacerbations, tachypnoea, skin changes (hirsutism, telangiectasia, perspiration), death at the age of 2-3 years. The biochemical changes in all children included raised serum levels of lactic acid, pyruvic acid and alanine, and acid-base equilibrium disturbances with metabolic acidosis (relatively balanced respiratory alkalosis). The results of the test of intravenous loading with glucose and alanine carried out in all children indicated indirectly reduced activity of pyruvate carboxylase. In one child histological examination of the brain carried out postmortem confirmed the diagnosis of Leigh's disease.
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PMID:[Suspected pyruvate carboxylase deficiency in 4 children with Leigh disease]. 309 72

Acute respiratory alkalosis (blood pH, 7.60; arterial PCO2, 15 mmHg (1 mmHg = 133.322 Pa); plasma bicarbonate, 14 mM) was induced in nine anesthetized dogs by increasing their respiratory rate and depth. Renal glutamine extraction and ammonia production expressed per 100 mL of glomerular filtration rate did not change during acute hypocapnia, whereas arterial glutamine concentration decreased significantly from 0.47 to 0.36 mM. Hypocapnia did not change plasma potassium concentration and its urinary excretion. Acute hypocapnia increased lactate extraction and pyruvate production, whereas citrate extraction and glutamate and alanine production did not change. Citraturia remained minimal. Renal cortical glutamine concentration fell from 0.64 to 0.38 mM during hypocapnia while alpha-ketoglutarate, glutamate, malate, oxaloacetate, and citrate did not change. Lactate concentration rose from 1.1 to 2.0 mM. Glutamine concentration in the liver and muscle decreased following acute hypocapnia. Our data are compatible with the hypothesis that an acute respiratory alkalosis might not result in any change in the hydrogen ion concentration and (or) gradient between the mitochondrial matrix and the cytosol. Consequently, renal glutamine extraction and ammonia production are not reduced, renal cortical concentrations of relevant metabolites in the ammoniagenic pathway are not changed, and renal handling of citrate remains unaffected.
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PMID:Renal metabolism and ammoniagenesis during acute respiratory alkalosis in the dog. 649 24


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