Regulation of fructose 2,6-bisphosphate concentration in white adipose tissue.
Injection of insulin to fed rats diminished the concentration of fructose 2,6-bisphosphate in white adipose tissue. Incubation of epididymal fat-pads or adipocytes with insulin stimulated lactate release and sugar detritiation and also decreased fructose 2,6-bisphosphate concentration. Such a decrease was, however, not observed in fat-pads from starved or alloxan-diabetic rats. Incubation of adipocytes from fed rats with various concentrations of glucose or fructose led to a dose-dependent rise in fructose 2,6-bisphosphate which correlated with lactate output and detritiation of 3-3H-labelled sugar. In adipocytes from fed rats, palmitate stimulated the detritiation of [3-3H]glucose without affecting lactate production and fructose 2,6-bisphosphate concentration. Incubation of epididymal fat-pads from fed rats in the presence of antimycin stimulated lactate output but decreased fructose 2,6-bisphosphate concentration. Changes in lipolytic rates brought about by noradrenaline, insulin, adenosine and corticotropin in adipocytes from fed rats were not related to changes in fructose 2,6-bisphosphate or to rates of lactate output. In fed rats, the activity of 6-phosphofructo-2-kinase was not changed after treatment of adipocytes with insulin, noradrenaline or adenosine. It is suggested that the decrease in fructose 2,6-bisphosphate concentration observed after insulin treatment can be explained by the increase in sn-glycerol 3-phosphate, an inhibitor of 6-phosphofructo-2-kinase.
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D000241:Adenosine / Q000494:pharmacology; D000273:Adipose Tissue / Q000187:drug effects / Q000378:metabolism*; D000324:Adrenocorticotropic Hormone / Q000494:pharmacology; D000818:Animals; D050260:Carbohydrate Metabolism; D005635:Fructosediphosphates / Q000378:metabolism*; D005990:Glycerol / Q000378:metabolism; D006598:Hexosediphosphates / Q000378:metabolism*; D066298:In Vitro Techniques; D007328:Insulin / Q000494:pharmacology; D007773:Lactates / Q000378:metabolism; D019344:Lactic Acid; D008066:Lipolysis / Q000187:drug effects; D008297:Male; D009638:Norepinephrine / Q000494:pharmacology; D010732:Phosphofructokinase-1 / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains
D005635:Fructosediphosphates; D006598:Hexosediphosphates; D007328:Insulin; D007773:Lactates; D019344:Lactic Acid; C027652:fructose 2,6-diphosphate; D000324:Adrenocorticotropic Hormone; D010732:Phosphofructokinase-1; D000241:Adenosine; D005990:Glycerol; D009638:Norepinephrine