Stimulation of glycolysis as an activation signal in rat peritoneal macrophages. Effect of glucocorticoids on this process.
1. Peritoneal macrophages were prepared from control, Escherichia coli-treated and triamcinolone acetonide-treated rats. Control and E. coli-treated rats produced resident and activated macrophages respectively. Glycolysis in these cells was studied by the fructose 2,6-bisphosphate (Fru-2,6-P2) content, lactate release and 6-phosphofructo-1-kinase (PFK-1) and 6-phosphofructo-2-kinase (PFK-2) activities. 2. In activated macrophages, lactate release and Fru-2,6-P2 content were increased several-fold compared with those in resident cells. Moreover, the response of these parameters to phorbol 12-myristate 13-acetate in activated macrophages was greater than for resident cells. 3. PFK-2 activity was moderately increased (about 3-fold), but PFK-1 activity was increased 5-fold in activated macrophages compared with resident cells. Partially purified preparations of PFK-1 were sensitive to Fru-2,6-P2, with K0.5 about 0.25 microM in both control and activated cells. However, the Vmax. of PFK-1 from activated cells was increased. In addition, AMP stimulated PFK-1, but the kinetic pattern was different from that described for Fru-2,6-P2. Moreover there was no difference in the stimulation by AMP of PFK-1 from resident and activated cells. 4. Fru-2,6-P2 content and lactate release in macrophages from triamcinolone acetonide-treated rats were decreased in both resident and activated cells. Also, the glucocorticoid inhibited PFK-1 and PFK-2 activities in both resident and activated macrophages. PFK-1 from triamcinolone acetonide-treated rats was not stimulated by Fru-2,6-P2, whereas the effect of AMP was unchanged. The effects of glucocorticoid seem to be specific for phagocytic cells, since the glucocorticoid treatment increased PFK-1 and PFK-2 activities in liver.
Bustos
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R
Departamento de Bioquímica Médica y Biología Molecular, Facultad de Medicina, Universidad de Sevilla, Spain.
Sobrino
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F
D000818:Animals; D004926:Escherichia coli; D005635:Fructosediphosphates / Q000378:metabolism; D006019:Glycolysis / Q000187:drug effects; D066298:In Vitro Techniques; D007700:Kinetics; D007773:Lactates / Q000378:metabolism; D008262:Macrophage Activation; D008264:Macrophages / Q000187:drug effects / Q000378:metabolism*; D008297:Male; D010732:Phosphofructokinase-1 / Q000378:metabolism; D025481:Phosphofructokinase-2; D010770:Phosphotransferases / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains; D012016:Reference Values; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D014222:Triamcinolone Acetonide / Q000494:pharmacology*
D005635:Fructosediphosphates; D007773:Lactates; C027652:fructose 2,6-diphosphate; D010770:Phosphotransferases; D025481:Phosphofructokinase-2; D010732:Phosphofructokinase-1; D014222:Triamcinolone Acetonide; D013755:Tetradecanoylphorbol Acetate