J. Biol. Chem., Vol. 260, Issue 5, 2621-2624, Mar, 1985
Balanced contribution of glycolytic and adenylate pool in supply of metabolic energy in platelets
AJ Verhoeven, ME Mommersteeg and JW Akkerman
When platelets are treated with H2O2 the metabolic ATP content decreases
sharply (Holmsen, H., and Robkin, L. (1977) J. Biol. Chem. 252, 1752-1757).
Here we report that the loss of metabolic energy is fully recovered in
phosphorylated glycolytic intermediates. A mixture of antimycin
A/2-deoxy-D-glucose/D-gluconic acid-1,5-lactone blocks mitochondrial ATP
resynthesis and prevents the entry of sugars into the glycolytic sequence.
The energy-rich phosphates in the adenylate and the glycolytic pool are
then consumed in a specific order. First, the glycolytic pool is consumed
at a rate of 4.5 mumol of ATP equivalents/min/10(11) cells, and metabolic
ATP and ADP are kept stable; then the consumption of the glycolytic pool
decreases and metabolic ATP and ADP are consumed, together keeping up with
the same rate of energy consumption. Thrombin stimulation increases the
energy consumption to about 17 mumol of ATPeq/min/10(11) cells which is now
furnished by both the glycolytic and the adenylate pool, again with a
preferential consumption of the former. The results show that H2O2 triggers
a shift of energy-rich phosphates from the adenylate to the glycolytic pool
and that the latter remains rapidly accessible to energy consumption
thereby stabilizing the level of metabolic ATP. The adenylate energy charge
is independent of the distribution of energy among the two pools, which
extends its importance to the regulation of energy supply and demand beyond
the adenylate pool.