Stimulation of phosphoenolpyruvate carboxylase activity in rust-infected wheat leaves

1974 ◽  
Vol 30 (9) ◽  
pp. 986-988 ◽  
Author(s):  
E. R. Waygood ◽  
L. Y. Pao ◽  
H. R. Godavari
Keyword(s):  
Phosphoenolpyruvate Carboxylase ◽  
Carboxylase Activity ◽  
Wheat Leaves ◽  
Stimulation Of

scholarly journals Regulation of mitochondrial pyruvate carboxylation in isolated hepatocytes by acute insulin treatment

1983 ◽  
Vol 214 (2) ◽  
pp. 451-458 ◽  
Author(s):  
A B Chisholm ◽  
E H Allan ◽  
M A Titheradge
Keyword(s):  
Insulin Treatment ◽  
Second Messengers ◽  
Isolated Hepatocytes ◽  
Carboxylase Activity ◽  
Effector Molecules ◽  
Pyruvate Carboxylation ◽  
Isolated Mitochondria ◽  
Glucose Synthesis ◽  
Important Site ◽  
Stimulation Of

The effect of acute insulin treatment of hepatocytes on pyruvate carboxylation in both isolated mitochondria and cells rendered permeable by filipin was examined. Challenging the cells with insulin alone had no effect on either the basal rate of pyruvate carboxylation or gluconeogenesis, although it did suppress the responses to both glucagon and catecholamines. Insulin treatment was unable to antagonize the enhanced rate of pyruvate carboxylation caused by stimulation of the cells with either angiotensin or vasopressin. Neither insulin nor the gluconeogenic hormones altered the total extractable pyruvate carboxylase activity in the isolated mitochondria, suggesting that the effect of hormones at the level of the isolated intact organelle was mediated via alterations in the intramitochondrial concentrations of effector molecules, notably ATP and the [ATP]/[ADP] ratio and substrate availability. The alterations in pyruvate carboxylation correlate well with glucose synthesis in terms of sensitivity to effector molecules, putative second messengers and time of onset of the response, indicating that alterations in the flux through this enzyme are compatible with it being an important site in the control of gluconeogenesis from C3 precursors.

scholarly journals Relationship between NH+4 Assimilation Rate and in Vivo Phosphoenolpyruvate Carboxylase Activity

1990 ◽  
Vol 94 (1) ◽  
pp. 284-290 ◽  
Author(s):  
Greg C. Vanlerberghe ◽  
Kathryn A. Schuller ◽  
Ronald G. Smith ◽  
Regina Feil ◽  
William C. Plaxton ◽  
...  
Keyword(s):  
Phosphoenolpyruvate Carboxylase ◽  
Assimilation Rate ◽  
Carboxylase Activity

scholarly journals A study of stabilization of gluconeogenic activity in rat liver slices by calcium and manganese ions

1972 ◽  
Vol 129 (2) ◽  
pp. 231-239 ◽  
Author(s):  
Anne Roobol ◽  
G. A. O. Alleyne
Keyword(s):  
Rat Liver ◽  
Phosphoenolpyruvate Carboxylase ◽  
Incubation Medium ◽  
Lysosomal Enzymes ◽  
Glucose Production ◽  
Liver Slice ◽  
Manganese Ions ◽  
Slice Preparation ◽  
Carboxylase Activity ◽  
Bivalent Cations

1. The effect of some bivalent cations on gluconeogenesis by the rat liver-slice preparation has been investigated. 2. Ca2+and Mn2+stimulated glucose production from a range of substrates but not from glycerol. Mg2+had no effect on the rate of glucose production. 3. Ca2+were required to maintain phosphoenolpyruvate carboxylase activity in the slice preparation. 4. Ca2+and Mn2+, but not Mg2+, retarded the release of lysosomal enzymes from the slice into the incubation medium. 5. It is proposed that Ca2+and Mn2+stimulate glucose production by stabilizing the lysosome system in the liver-slice preparation. 6. The value of the liver-slice preparation as a means of measuring hepatic gluconeogenesis is discussed.

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