The Development of Glycolytic and Pentose Phosphate Shunt Enzymes in Human Brain

Neonatology ◽  
1977 ◽  
Vol 31 (3-4) ◽  
pp. 173-180 ◽  
Author(s):  
M.J. Bennett ◽  
W.R. Timperley ◽  
C.B. Taylor ◽  
A.S. Hill
Keyword(s):  
Human Brain ◽  
Pentose Phosphate ◽  
Pentose Phosphate Shunt

scholarly journals Impaired erythrocyte phosphoribosylpyrophosphate formation in hemolytic anemia due to pyruvate kinase deficiency

Blood ◽  
1988 ◽  
Vol 72 (2) ◽  
pp. 500-506 ◽  
Author(s):  
CR Zerez ◽  
MD Wong ◽  
NA Lachant ◽  
KR Tanaka
Keyword(s):  
Pyruvate Kinase ◽  
Hemolytic Anemia ◽  
Adenosine Triphosphate ◽  
Pyridine Nucleotide ◽  
Pentose Phosphate ◽  
Atp Depletion ◽  
Pyridine Nucleotides ◽  
Pyruvate Kinase Deficiency ◽  
Nucleotide Content ◽  
Pentose Phosphate Shunt

Abstract RBCs from patients with hemolytic anemia due to pyruvate kinase (PK) deficiency are characterized by a decreased total adenine and pyridine nucleotide content. Because phosphoribosylpyrophosphate (PRPP) is a precursor of both adenine and pyridine nucleotides, we investigated the ability of intact PK-deficient RBCs to accumulate PRPP. The rate of PRPP formation in normal RBCs (n = 11) was 2.89 +/- 0.80 nmol/min.mL RBCs. In contrast, the rate of PRPP formation in PK-deficient RBCs (n = 4) was markedly impaired at 1.03 +/- 0.39 nmol/min.mL RBCs. Impaired PRPP formation in these cells was not due to the higher proportion of reticulocytes. To study the mechanism of impaired PRPP formation, PK deficiency was simulated by incubating normal RBCs with fluoride. In normal RBCs, fluoride inhibited PRPP formation, caused adenosine triphosphate (ATP) depletion, prevented 2,3-diphosphoglycerate (DPG) depletion, and inhibited pentose phosphate shunt (PPS) activity. These results together with other data suggest that impaired PRPP formation is mediated by changes in ATP and DPG concentration, which lead to decreased PPS and perhaps decreased hexokinase and PRPP synthetase activities. Impaired PRPP formation may be a mechanism for the decreased adenine and pyridine nucleotide content in PK-deficient RBCs.

A STUDY OF GLYCOLYTIC AND PENTOSE PHOSPHATE SHUNT ENZYMES IN RELATIONSHIP TO THE ALTERED PERMEABILITY IN THE BLOOD-BRAIN BARRIER

1976 ◽  
Vol 26 (6) ◽  
pp. 1139-1143 ◽  
Author(s):  
M. J. Bennett ◽  
K. M. Ogilvy. ◽  
G. M. Blake ◽  
N. Lewtas ◽  
W. R. Timperley
Keyword(s):  
Blood Brain Barrier ◽  
Pentose Phosphate ◽  
Brain Barrier ◽  
Blood Brain ◽  
Pentose Phosphate Shunt

scholarly journals Effects of Kinetin on Respiration Ethylene Production and Ripening of Banana Fruit Slices

1971 ◽  
Vol 24 (1) ◽  
pp. 165 ◽  
Author(s):  
NL Wade ◽  
CJ Brady
Keyword(s):  
Indoleacetic Acid ◽  
Phosphate Uptake ◽  
Invertase Activity ◽  
Pentose Phosphate ◽  
Plant Tissues ◽  
Banana Fruit ◽  
Solute Uptake ◽  
Thin Slices ◽  
Tissue Changes ◽  
Pentose Phosphate Shunt

Thin slices cut from many plant tissues develop an increased respiration rate in the day or days after cutting (Laties 1963; ap Rees 1966). Mter slicing, the metabolism of the tissue changes in a number of respects including the capacity for salt and other solute uptake (Asprey 1937; MacDonald 1967), the relative contri-bution of the pentose phosphate shunt to total hexose catabolism !ap Rees and Beevers 1960; ap Rees 1966), and the induction of a number of enzymes (Edelman and Hall 1965; Willemot and Stumpf 1967). In the case of slices of arti-choke tissue, the presence of either indoleacetic acid or kinetin inhibits the increases, in response to slicing, of respiration, of phosphate uptake, and of invertase activity (Palmer 1966). While aspects of the latter experiments have been criticized (Vaughan and MacDonald 1967) the conclusion that the growth factors affect the response to slicing has not been challenged.

Activities of Enzymes for Glucose Catabolism in the Swimbladder of the European Eel Anguilla Anguilla

1991 ◽  
Vol 156 (1) ◽  
pp. 207-213 ◽  
Author(s):  
BERND PELSTER ◽  
PETER SCHEID
Keyword(s):  
White Muscle ◽  
Anguilla Anguilla ◽  
Great Depth ◽  
Pentose Phosphate ◽  
European Eel ◽  
Glucose Catabolism ◽  
Rete Mirabile ◽  
Special Adaptation ◽  
Glucose 6 Phosphate Dehydrogenase ◽  
Pentose Phosphate Shunt

Gas secretion into the swimbladder of the eel relies on the production of CO2 and lactic acid from glucose in the swimbladder epithelium. The activities of the enzymes involved in glucose catabolism have been measured and compared with those in the rete mirabile, the liver and white skeletal muscle to evaluate whether the pentose phosphate shunt may contribute to glucose metabolism in the swimbladder tissue. The activities of enzymes of the pentose phosphate shunt were higher in the swimbladder epithelium than in white muscle, and close to those in the liver. The activities of the enzymes of anaerobic glycolysis were 2–5 times higher in the swimbladder epithelium than in the rete mirabile, reaching or even exceeding the levels in liver and white muscle, whereas the activities of the enzymes of oxidative metabolism were extremely low. Compared to enzymes of the other tissues, swimbladder phosphofructokinase and glucose-6-phosphate dehydrogenase showed no special adaptation to low pH values. The results show that the swimbladder epithelium is equipped with enzymes that produce CO2 from glucose without the removal of O2, which is particularly advantageous for creating the high gas partial pressures needed for filling the swimbladder at great depth.

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