Biomedical subjects

K R Tanaka

Publications and source records attributed to K R Tanaka.

At least 55 records · Page 3Linked to original sources

PubMed1984

Antioxidant metabolism during blood storage and its relationship to posttransfusion red cell survival.

The status of the erythrocyte antioxidant defense system and its relationship to posttransfusion red cell survival were determined in erythrocytes stored for 35 or 42 days in CPD-A1 anticoagulant with a saline-adenine-glucose additive. As storage progressed, there was a significant increase in incubated Heinz body formation (P less than .001) and a significant decrease in reduced glutathione (GSH) stability (P less than .001). Stimulated pentose phosphate shunt activity also declined during storage (P less than .06), while unstimulated shunt activity remained unchanged. The increase in Heinz body formation was associated with decreased GSH stability (r = -.77, P less than .001), which in turn was associated with the decline in stimulated pentose shunt activity (r = .67, P less than .001). The changes in Heinz body formation (r = -.85), GSH stability (r = .83), and stimulated pentose shunt activity (r = .54) were all significantly (P less than .001) related to the decline in adenosine triphosphate (ATP) content of the erythrocyte. Red cell survival 24 hours after transfusion was significantly related to the GSH stability (r = .80, P less than .001) and to the ATP concentration (r = .76, P less than .005) on the day of transfusion. Thus, dysfunction of the erythrocyte antioxidant defense system occurs during blood storage and appears to be related, in part, to ATP depletion. The ability to maintain a normal reduced glutathione concentration during oxidant stress appears to be an important determinant of red cell survival in the peritransfusion period.

Adenosine Triphosphate↗

PubMed1984

Association of hemolytic anemia and early-onset pulmonary emphysema in three siblings.

Three of four siblings born to nonconsanguineous parents of Italian origin were affected with severe congenital hemolytic anemia of unknown cause, and early-onset pulmonary emphysema. Two of the three affected siblings died of septic shock after splenectomy, at the ages of 7 and 3 1/2 years, respectively. The remaining affected sibling was shown to have cutis laxa and severe pulmonary emphysema at 15 years of age. Assay of serum components indicated that alpha 1-antitrypsin and alpha 2-macroglobulin levels were normal or slightly elevated. However, there was markedly elevated activity of an elastase-like serum enzyme. The relation of the hemolytic anemia to the pulmonary findings in this family is not clear; pedigree analysis suggests a recessively inherited defect.

Adolescent↗

PubMed1984

CDP-choline does not inhibit erythrocyte glycolytic or pentose phosphate pathway enzyme activity.

An increased concentration of cytidine diphosphocholine (CDP-choline) has been observed in erythrocytes in the hemolytic anemia due to hereditary pyrimidine 5'-nucleotidase deficiency (P5Nase, EC 3.1.3.5) and in a patient with a chronic hemolytic anemia not due to P5Nase deficiency, as reported by Paglia and co-workers in 1983. In the current studies, we were unable to demosntrate a significant inhibitory effect of 4 mmol/l CDP-choline on the activities of the enzymes of the Embden-Meyerhof and pentose phosphate pathways. The physiologic significance of increased erythrocytic CDP-choline remains to be determined.

Choline↗

PubMed1984

Inhibition of the pentose phosphate shunt by lead: a potential mechanism for hemolysis in lead poisoning.

Recent investigations have disclosed a decrease in pentose phosphate shunt activity in hereditary pyrimidine 5'-nucleotidase deficiency. Clinical lead poisoning is associated with an acquired decrease in pyrimidine 5'-nucleotidase activity. The current investigations were undertaken (1) to determine if pentose shunt activity was decreased in erythrocytes exposed to lead, and (2) to compare the mechanism of inhibition to that seen in hereditary pyrimidine 5'-nucleotidase deficiency. Normal erythrocytes incubated with lead acetate in vitro demonstrated increased Heinz body formation, decreased reduced glutathione, a positive ascorbate cyanide test, and a reversible suppression of pentose shunt activity in the intact erythrocyte. Lead acetate added to normal red cell hemolysates markedly inhibited the activities of glucose-6-phosphate dehydrogenase (G6PD) and phosphofructokinase. The mean Kis of lead for glucose-6-phosphate and nicotinamide adenine dinucleotide phosphate (NADP) for G6PD were 1.5 microM and 2.1 microM, respectively, which is within the range of intraerythrocytic lead concentrations found in clinical lead poisoning. Magnesium enhanced the ability of lead to inhibit G6PD. Thus, the shortened erythrocyte survival in lead poisoning appears to be due, in part, to increased oxidant sensitivity secondary to inhibition of G6PD and the pentose shunt. The mechanism of shunt inhibition is, in part, similar to that seen in hereditary pyrimidine 5'-nucleotidase deficiency.

5'-Nucleotidase↗

PubMed1983

Octopamine in Lumbricus terrestris: presence, synthesis and effect of octopamine on the spontaneous rhythmic contractions of the ventral nerve cord.

A radiochemical-enzymatic assay was utilized to measure endogenous levels of octopamine in the nerve cord and blood of the earthworm. The results show the presence of octopamine in the ventral nerve cord and blood at concentrations of 2.79 +/- 0.5 (means +/- S.D.) ng/mg wet tissue weight and 9.5 +/- 1.6 x 10(-8) M (means +/- S.D.) respectively. The ability of the ventral nerve cord to synthesize octopamine was investigated by incubating the tissue in vitro in radiolabeled percursors. The results show the synthesis of [3H]octopamine from both precursor [3H]tyrosine and [3H]tyramine. In vitro incubation of the isolated ventral nerve cord in physiological concentrations of octopamine revealed modulation of the spontaneous rhythmic contractions of the nerve cord. The data provide direct support for a modulatory role of octopamine in L. terrestris.

Animals↗

PubMed1983

Impaired pentose phosphate shunt function in sickle cell disease: a potential mechanism for increased Heinz body formation and membrane lipid peroxidation.

The red cells' antioxidant defense mechanisms were compared between individuals with sickle cell disease and those with hemolytic anemia and reticulocytosis. In sickle cell disease, there was a significant increase in incubated Heinz body formation (p less than .001), a decrease in reduced glutathione concentration (p less than .01), an increase in glucose-6-phosphate dehydrogenase activity (p less than .01), and a decrease in glutathione reductase activity (p less than .005). The patients with sickle cell disease hd an absolute increase in the activity of the pentose shunt in the intact red cell after methylene blue stimulation (p less than .05) and in red cell hemolysates (p less than .0250. Heinz body formation (r = .75) and pentose shunt activity in red cell hemolysates (r = .83) were strongly related to the degree of reticulocytosis. Although there was a correlation between the pentose shunt activity in the stimulated red cell and in red cell hemolysates for the patients with hemolytic anemia (r = .58), stimulated shunt activity did not increase as the hemolysate shunt activity increased for the patients with sickle cell disease. There were very strong relationships between the ATP concentration and the reticulocyte count (r = .80) and the hemolysate pentose shunt activity (r = .77) in sickle cel disease. These data suggest that in spite of an absolute increase in stimulated pentose shunt activity, there Is a relative suppression of stimulated shunt activity in the youngest sickle erythrocytes. This may be related, in part, to the inhibitory effects of high concentrations of ATP on the activity of glucose-6-phosphate dehydrogenase.

2,3-Diphosphoglycerate↗

PubMed1983

Octopamine action on the spontaneous contractions of the isolated nerve cord of Lumbricus terrestris.

Octopamine and synephrine were observed to effect the spontaneous rhythmic contractions displayed by the isolated ventral nerve cord of the earthworm, Lumbricus terrestris. octopamine and synephrine produced dose-dependent significant changes in the frequency, amplitude and basal tonus of the spontaneous contractions. Application of adrenergic receptor antagonists suggested the octopamine receptors to have some similarity to vertebrate alpha 1-adrenergic receptors. The spontaneous contractions were not abolished by tetrodotoxin (TTX) which suggested a myogenic origin for the contraction of the ventral nerve cord sheath muscles. Octopamine, in the presence of TTX, increased the basal tonus and maximum force of the spontaneous contractions.

Adrenergic alpha-Antagonists↗

PubMed1983

Inhibition of the pentose phosphate shunt by 2,3-diphosphoglycerate in erythrocyte pyruvate kinase deficiency.

Pentose phosphate shunt activity was studied by the release of 14CO2 from 14C-1-glucose and 14C-2-glucose in the red cells of five patients with pyruvate kinase deficiency and found to be significantly decreased after new methylene blue stimulation when compared to high reticulocyte controls. Incubated Heinz body formation was increased and the ascorbate cyanide test was positive in blood from these patients. The activity of glucose-6-phosphate dehydrogenase (G6PD) as well as that of 6-phosphogluconate dehydrogenase (6PGD) was inhibited to 20% of baseline in normal red cell haemolysate by 4 mM 2,3-diphosphoglycerate at pH 7.1. 2,3-Diphosphoglycerate was a competitive inhibitor with 6-phosphogluconate (Ki=1.05 mM) and a noncompetitive inhibitor with NADP (Ki=3.3 mM) for 6PGD. Since the intracellular concentrations of glucose-6-phosphate, 6-phosphogluconate and NADP are below their Kms for G6PD and 6PGD, the kinetic data suggest that increased concentrations of 2,3-diphosphoglycerate in pyruvate kinase deficient red cells are sufficiently high to suppress pentose phosphate shunt activity. This suppression may be an additional factor contributing to the haemolytic anaemia of pyruvate kinase deficiency, particularly during periods of infection or metabolic stress.

2,3-Diphosphoglycerate↗

PubMed1983

Heterogeneity of the molecular lesions in inherited phosphofructokinase deficiency.

Human phosphofructokinase (PFK; EC 2.7.1.11) exists in tetrameric isozymic forms. Muscle and liver contain the homotetramers M4 and L4, whereas erythrocytes contain five isozymes composed of M (muscle) and L (liver) subunits, i.e., M4, M3L, M2L2, ML3, and L4. Inherited defects of erythrocyte PFK are usually partial and are described in association with heterogeneous clinical syndromes. To define the molecular basis and pathogenesis of this enzymopathy, we investigated four unrelated individuals manifesting myopathy and hemolysis (glycogenosis type VII), isolated hemolysis, or no symptoms at all. The three symptomatic patients showed high-normal hemoglobin levels, despite hemolysis and early-onset hyperuricemia. They showed total lack of muscle-type PFK and suffered from exertional myopathy of varying severity. In the erythrocytes, a metabolic crossover was evident at the PFK step: the levels of hexose monophosphates were elevated and those of 2,3-diphosphoglycerate (2,3-DPG) were depressed, causing strikingly increased hemoglobin-oxygen affinity. In all cases, the residual erythrocyte PFK consisted exclusively of L4 isozyme, indicating homozygosity for the deficiency of the catalytically active M subunit. However, presence of immunoreactive M subunit was shown in cultured fibroblasts by indirect immunofluorescence with monoclonal anti-M antibody. The fourth individual was completely asymptomatic, had normal erythrocyte metabolism, and had no evidence of hemolysis. His residual erythrocyte PFK showed a striking decrease of the L4, ML3, and M2L2 isozymes, secondary to a mutant unstable L subunit. Identical alterations of erythrocyte PFK were found in his asymptomatic son, indicating heterozygosity for the mutant unstable L subunit in this kindred. These studies show that, except for the varying severity of the myopathic symptoms, glycogenosis type VII has highly uniform clinical and biochemical features and results from homozygosity for mutant inactive M subunit(s). The absence of anemia despite hemolysis may be explained by the low 2,3-DPG levels. The hyperuricemia may result from hyperactivity of the hexose monophosphate shunt. In contrast, the clinically silent carrier state results from heterozygosity for mutant M or L subunit. Of the two, the M subunit appears to be more critical for adequate glycolytic flux in the erythrocyte, since its absence is correlated with hemolysis.

Adult↗

PubMed1983

Mechanism of red cell 2,3-diphosphoglycerate increase in neonatal lambs.

The tenfold increase in red cell 2,3-diphosphoglycerate (DPG) concentration that occurs during the first 5 days of life in lambs is an important adaptation to extrauterine life. In lambs, DPG reduces hemoglobin oxygen affinity by the Bohr effect. Our data on 10 neonatal lambs suggest that the biochemical mechanism underlying this DPG increase involves the following: (1) a rise in plasma glucose from 40 to 100 mg/dl in the first 48 hr of life, which allows for increased glucose consumption in the highly glucose-permeable neonatal RBC; (2) a transitory rise in blood pH begins at birth, peaks at about 20 hr, and falls slightly; (3) the pH increase coincides with a threefold increase in RBC fructose-1,6-diphosphate (FDP) concentration due, we believe, to pH activation of phosphofructokinase; (4) glycolytic intermediates after the glyceraldehyde-3-phosphate dehydrogenase (GAPD) step do not rise in the first 24 hr of life, possibly due to insufficient inorganic phosphate (Pi), a substrate of GAPD; (5) plasma Pi increases from about 7 mg/dl at birth to 11 mg/dl at 72 hr, activates the GAPD, and FDP levels decline; and (6) the in vitro activity of the DPG synthetic enzyme, DPG mutase, is increased 12-fold in neonatal compared to adult RBC. We conclude that the postnatal rise in DPG is explained at least in part by the sequential effects of these metabolic changes.

2,3-Diphosphoglycerate↗

PubMed1982

Red cell enzyme activity during blood storage and reactivation of phosphofructokinase.

Activities of 21 red cell enzymes were measured in 15 units of CPD-Al anticoagulated blood before and after 35 days of storage. Paired t-tests revealed that five of the enzyme activities decreased significantly after 35 days of storage (P less than 0.05) while four increased significantly after storage (P less than 0.05). The most striking change was in phosphofructokinase (PFK), which decreased an average of 33% (P less than 0.005). Mean lactate dehydrogenase activity increased to 128% of its zero-day activity (P less than 0.005). Percent red cell survival, determined by reinfusion of a 51Cr-tagged aliquot of stored blood into the autologous donor, was highly correlated with 35-day ATP levels (r = 0.97; P less than 0.001). No significant relationships between two measures of red cell survival and any of the nine significantly altered enzymes were found. Studies of reactivation of PFK in hemolysates using 4 mM concentrations of numerous compounds indicate that the compounds or combinations of compounds used which reactivate PFK significantly all contain at least one high-energy phosphate group. These data suggest that loss of PFK activity during storage may be due to loss of organic phosphates. Whether the changes described have an important role in blood transfusion remains to be determined.

Adenosine Triphosphate↗

PubMed1982

Erythrocyte isozymes of phosphofructokinase in genetically high- and low-2,3-diphosphoglycerate rats.

A major locus (Dpg) with two alleles (d and D) controls erythrocyte 2,3-diphosphoglycerate (DPG) levels in Long-Evans rats and is closely linked to a locus (Hbb) determining a hemoglobin electrophoretic polymorphism. Glycolytic intermediate levels and phosphofructokinase (PFK) kinetic studies suggest that in vivo PFK activity differences underlie the differences in DPG levels. We report here chromatographic and immunologic evidence that rat erythrocyte PFK is composed of two isozymes which elute from DEAE-Sephadex at positions identical to those of the isozymes in platelets and liver, respectively. The percentage of platelet-type PFK is significantly (P less than 0.05) smaller in low-DPG (dd) hemolysates than in DD hemolysates regardless of hemoglobin phenotype. When hemolysates were prepared in a stabilizing buffer, PFK specific activity was significantly (P less than 0.005) higher in DD rats. These data suggest that the PFK kinetic differences may result from alterations in the isozyme composition of active PFK.

2,3-Diphosphoglycerate↗

PubMed1982

Erythrocyte enzymes in Ovis aries. Effect of cell age.

1. Activities of 20 red cell enzymes were compared in 8 normal female Ovis Aries, in a serially bled ewe followed by 243 days, and in young and old red cell populations separated by density gradient centrifugation. 2. These comparisons indicate that the erythrocyte enzymes which show significant changes with cell age are glucose-6-phosphate dehydrogenase, 6-phosphogluconate dehydrogenase, hexokinase, phosphoglucose isomerase, lactate dehydrogenase, glutathione reductase, enolase and phosphoglycerate kinase. 3. The usefulness of these data in interpretation of enzyme activities from fetal Ovis Aries is discussed.

Animals↗

PubMed1982

Erythrocyte enzymes in sheep: comparison of activity in fetal, newborn, maternal and nonpregnant ewe erythrocytes.

Hematological data and the activities of 21 red cell enzymes were measured in 8 nonpregnant ewes, 13 chronically catheterized fetuses at 125-135 days of gestation, and 8 of their mothers. In addition, 7 lambs were followed from birth to 17 days of age. Fetal sheep red cells have dramatically increased activities for 17 of 21 enzymes measured compared with adult nonpregnant ewes. The pattern of decline of enzyme activities with development varies considerably among enzymes. The activity of seven enzymes showed an orderly decline from fetal to adult life. For seven enzymes very little or no decline in activity was observed between 125 and 135 days of gestation and birth. Pyruvate kinase activity declined to adult levels by birth. Phosphoglucose isomerase and nucleoside phosphorylase activity increased, and glutathione peroxidase activity decreased in newborn lamb red cells compared to fetal cells. Differences in blood cell variables were also found among these groups.

Aging↗

PubMed1982

Hemolytic anemia in hereditary pyrimidine 5'-nucleotidase deficiency: nucleotide inhibition of G6PD and the pentose phosphate shunt.

We evaluated the erythrocytes of two patients with hereditary pyrimidine 5'-nucleotidase deficiency. Significant findings included an increased reduced glutathione content, increased incubated Heinz body formation, a positive ascorbate cyanide test, and decreased intraerythrocytic pH. The pentose phosphate shunt activity of the patients' red cells as measured by the release of 14CO2 from 14C-1-glucose was decreased compared to high reticulocyte controls. Glucose-6-phosphate dehydrogenase (G6PD) activity in hemolysates from control erythrocytes was inhibited 43% by 5.5 mM cytidine 5'-triphosphate (CTP) and 50% by 5.5 mM in uridine 5'-triphosphate (UTP) at pH 7.1. CTP was a competitive inhibitor for G6P (Ki = 1.7 mM) and a noncompetitive inhibitor for NADP+ (Ki = 7.8 mM). Glutathione peroxidase, glutathione reductase, and 6-phosphogluconate dehydrogenase were not affected by these compounds. Pentose phosphate shunt activity in control red cell hemolysate at pH 7.1 was inhibited to a similar degree by 5.5 mM CTP or UTP. Since the intracellular concentrations of G6P and NADP+ are below their KmS for G6PD, these data suggest that high concentrations of pyrimidine 5'-nucleotides depress pentose phosphate shunt activity in pyrimidin 5'-nucleotidase deficiency. Thus, this impairment of the pentose phosphate pathway appears to contribute to the pathogenesis of hemolysis in pyrimidine 5'-nucleotidase deficiency hemolytic anemia.

5'-Nucleotidase↗

PubMed1981

Erythrocyte phosphofructokinase in rat strains with genetically determined differences in 2,3-diphosphoglycerate levels.

We have studied the erythrocyte enzyme phosphofructokinase (PFK) from two strains of Long-Evans rats with genetically determined differences in erythrocyte 2,3-diphosphoglycerate (DPG) levels. The DPG difference is due to two alleles at one locus. With one probable exception, the genotype at this locus is always associated with the hemoglobin (Hb) electrophoretic phenotype, due to a polymorphism at the III beta-globin locus. The enzyme PFK has been implicated in the DPG difference because glycolytic intermediate levels suggest that this enzyme has a higher in vivo activity in High-DPG strain rats, although the total PFK activity does not differ. We report here that partially purified erythrocyte PFK from Low-DPG strain cells is inhibited significantly more at physiological levels of DPG (P less than 0.01) than PFK from High-DPG strain erythrocytes. Citrate and adenosine triphosphate also inhibit the Low-DPG enzyme more than the High-DPG enzyme. Therefore, a structurally different PFK, with a greater sensitivity to inhibitors, may explain the lower DPG and ATP levels observed in Low-DPG strain animals. These data support a two-locus (Hb and PFK) hypothesis and provide a gene marker to study the underlying genetic and physiologic relationships of these loci.

Adenosine Triphosphate↗

PubMed1981

Hexose monophosphate shunt metabolism in sheep: comparison of fetal, newborn and adult erythrocytes.

Glucose utilization through the hexose monophosphate shunt was measured in erythrocytes from fetal sheep, newborn lambs and adult pregnant sheep. Fetal erythrocytes demonstrate dramatically increased glucose oxidation in the presence of the oxidant new methylene blue. This response declines by birth and thereafter until adult sheep erythrocytes show no response. No stimulation was observed in adult sheep red cells under a number of conditions, although when adult sheep red cells were separated according to cell age, young cells were found to respond greatly to new methylene blue. When the rate of glucose oxidation after new methylene blue stimulation is correlated with in vitro glucose-6-phosphate dehydrogenase activity, a highly significant relationship is seen. This suggests that developmental changes in glucose oxidation by sheep red cells may be due to similar changes in glucose-6-phosphate dehydrogenase activity. The relationship also suggests that mature adult erythrocytes may be unable to respond to oxidants because of their low glucose-6-phosphate dehydrogenase activity.

Animals↗

PubMed1980

Pituitary-adrenal axis function in sickle cell anemia and its relationship to leukocyte alkaline phosphatase.

The function of the pituitary-adrenal axis and leukocyte alkaline phosphatase activity were evaluated in eight patients with sickle cell disease during a painful crisis and when crisis-free. The leukocyte alkaline phosphatase (LAP) score did not increase during crisis; the scores were in the low-normal range during crisis and noncrisis periods. Insulin-induced hypoglycemia produced normal growth hormone responses during both crisis and crisis-free periods. Plasma cortisol concentrations were diminished in the crisis group. Also impaired was 11-deoxycortisol production in both groups after metyrapone. These findings indicate that a mild defect in the hypothalamic-pituitary-adrenal axis exists in sickle cell disease patients.

Adult↗