Evidence that insulin deficiency in the rat has disparate effects on fructose 2,6-bisphosphate levels in muscle and liver.
The level of fructose 2,6-bisphosphate (F2,6P2), a potent stimulator of 6-phosphofructo-1-kinase and inhibitor of fructose 1,6-bisphosphatase, was measured in three different muscle types (tensor fascia latae, biceps femoris, and soleus) and in the liver of normal and diabetic rats. The mean (+/- SEM) content of F2,6P2 (nanomoles per g tissue) varied among the three types of skeletal muscle in normal rats, with the biceps femoris having the highest (0.97 +/- 0.15) and the soleus the lowest (0.57 +/- 0.03) levels. However, these differences were unrelated to simultaneous estimates of skeletal muscle activity of 6-phosphofructo-1-kinase activity. The total concentration of F2,6P2 was more than 8-fold higher (8.5 +/- 0.9) in the liver, and this value fell to 5.3 +/- 0.8 (P less than 0.05) after the induction of diabetes with streptozotocin. In contrast, F2,6P2 levels did not fall in skeletal muscle of rats with streptozotocin-induced diabetes, and the concentration actually increased. Thus, the fall in hepatic F2,6P2 concentration associated with insulin deficiency was not observed in skeletal muscle.
D000818:Animals; D003921:Diabetes Mellitus, Experimental / Q000378:metabolism*; D005635:Fructosediphosphates / Q000378:metabolism*; D006598:Hexosediphosphates / Q000378:metabolism*; D007328:Insulin / Q000502:physiology*; D008099:Liver / Q000378:metabolism*; D008297:Male; D009132:Muscles / Q000378:metabolism*; D010732:Phosphofructokinase-1 / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains
D005635:Fructosediphosphates; D006598:Hexosediphosphates; D007328:Insulin; C027652:fructose 2,6-diphosphate; D010732:Phosphofructokinase-1