Carbon-13 NMR study of the effects of fasting and diabetes on the metabolism of pyruvate in the tricarboxylic acid cycle and of the utilization of pyruvate and ethanol in lipogenesis in perfused rat liver

Biochemistry ◽  
1987 ◽  
Vol 26 (2) ◽  
pp. 581-589 ◽  
Author(s):  
Sheila M. Cohen
Keyword(s):  
Rat Liver ◽  
Tricarboxylic Acid Cycle ◽  
Tricarboxylic Acid ◽  
Perfused Rat Liver ◽  
Acid Cycle ◽  
Nmr Study

scholarly journals The stimulation of tricarboxylic acid-cycle flux by α-adrenergic agonists in perfused rat liver

1986 ◽  
Vol 233 (2) ◽  
pp. 321-324 ◽  
Author(s):  
W M Taylor ◽  
E van de Pol ◽  
F L Bygrave
Keyword(s):  
Rat Liver ◽  
Tricarboxylic Acid Cycle ◽  
Tricarboxylic Acid ◽  
Perfused Rat Liver ◽  
Adrenergic Agonists ◽  
Acid Cycle ◽  
Total Tissue ◽  
Stimulation Of

Output of 14CO2 from 1-14C-labelled glutamate, 2-oxoglutarate or octanoate and from 4-methyl-2-oxo[2-14C]pentanoate was increased by more than 100% after infusion of phenylephrine into perfused livers of fed rats. Infusion of ethanol or sorbitol raised 3-hydroxybutyrate/acetoacetate ratios and decreased the output of 14CO2. Increases in 14CO2 output induced by phenylephrine were observed in the presence or absence of ethanol or sorbitol and were accompanied by elevated 3-hydroxybutyrate/acetoacetate ratios under all conditions examined. Phenylephrine had no effect on total tissue ATP/ADP ratios in livers from fed or starved rats. The data suggest that phenylephrine-induced increases in tricarboxylic acid-cycle flux do not arise from lowered matrix NADH/NAD+ or ATP/ADP ratios.

scholarly journals The redistribution of carbon label by the reactions involved in glycolysis, gluconeogenesis and the tricarboxylic acid cycle in rat liver

1968 ◽  
Vol 110 (2) ◽  
pp. 313-335 ◽  
Author(s):  
D. F. Heath
Keyword(s):  
Carbon Dioxide ◽  
Steady State ◽  
Rat Liver ◽  
Tricarboxylic Acid Cycle ◽  
Specific Radioactivity ◽  
Tricarboxylic Acid ◽  
State Theory ◽  
Variable Rate ◽  
Acid Cycle ◽  
Constant Rate

A scheme is presented that shows how the reactions involved in gluconeogenesis, glycolysis and the tricarboxylic acid cycle are linked in rat liver. Equations are developed that show how label is redistributed in aspartate, glutamate and phosphopyruvate when it is introduced as specifically labelled pyruvate or glucose either at a constant rate (steady-state theory) or at a variable rate (non-steady-state theory). For steady-state theory the fractions of label introduced as specifically labelled pyruvate that are incorporated into glucose and carbon dioxide are also given, and for both theories the specific radioactivities of aspartate and glutamate relative to the specific radioactivity of the substrate. The theories allow for entry of label into the tricarboxylic acid cycle via both oxaloacetate and acetyl-CoA, for 14CO2 fixation and for loss of label from the tricarboxylic acid cycle in glutamate, but not for losses in citrate. They also allow for incomplete symmetrization of label in oxaloacetate due to incomplete equilibration with fumarate both in the extramitochondrial part of the cell and in the mitochondrion on entry of oxaloacetate into the tricarboxylic acid cycle. In the latter case failure both of oxaloacetate to equilibrate with malate and of malate to equilibrate with fumarate are considered.

THE EFFECT OF NEUTRAL SALTS ON PARTICLE PREPARATIONS FROM RAT LIVER: II. EFFECTS OF NEUTRAL SALTS ON TRICARBOXYLIC ACID CYCLE REACTIONS

1965 ◽  
Vol 43 (3) ◽  
pp. 359-372 ◽  
Author(s):  
E. R. Tustanoff ◽  
H. B. Stewart
Keyword(s):  
Rat Liver ◽  
Acid Metabolism ◽  
Tricarboxylic Acid Cycle ◽  
Tricarboxylic Acid ◽  
Neutral Salt ◽  
Acid Cycle ◽  
Pyruvate Oxidation ◽  
Highly Sensitive ◽  
Osmotic Activity

In a previous paper it was shown that neutral salt or sucrose, probably as a consequence of osmotic activity, interferes with the utilization of pyruvate by washed particle preparations from rat liver. In the present paper the effects of neutral salt on reaction sequences in the tricarboxylic acid cycle have been investigated. α-Oxoglutarate utilization is inhibited by salt in a fashion that closely resembles the osmolar inhibition of pyruvate oxidation. Citrate, but not cis-aconitate or isocitrate, utilization is inhibited by salt concentrations somewhat greater than those required for inhibition of α-oxo acid metabolism. Succinate, fumarate, and malate utilization are not highly sensitive to salt inhibition, and anaerobic utilization of citrate in the presence of 1,10-phenanthroline does not appear to be affected by salt.

Cutaneous Burn Injury Alters Relative Tricarboxylic Acid Cycle Fluxes in Rat Liver

1999 ◽  
Vol 20 (4) ◽  
pp. 292-302 ◽  
Author(s):  
David M. Yarmush ◽  
Annette D. MacDonald ◽  
Brent D. Foy ◽  
Francois Berthiaume ◽  
Ronald G. Tompkins ◽  
...  
Keyword(s):  
Rat Liver ◽  
Burn Injury ◽  
Tricarboxylic Acid Cycle ◽  
Tricarboxylic Acid ◽  
Acid Cycle
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