Oral administration of vanadate to diabetic rats restores liver 6-phosphofructo-2-kinase content and mRNA.
Vanadate and insulin were administered to diabetic (streptozotocin) rats to compare their effects on the activity and mRNA content of 6-phosphofructo-2-kinase and L-type pyruvate kinase in the liver. The activity of 6-phosphofructo-2-kinase in livers of diabetic rats was about 40% of that found in normal rats. A similar decrease was found for 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase content, measured by immunoprecipitation, and for mRNA, measured by hybridization of Northern blots. Administration of vanadate to the diabetic rats led to a progressive recovery of 6-phosphofructo-2-kinase activity, and 6-phosphofructo-2-kinase/fructose- 2,6-bisphosphatase content and mRNA. This recovery, which was complete after 15 days of oral treatment, was also obtained after 60 h of insulin administration. L-type pyruvate kinase activity and mRNA were also decreased by about 70% in livers of diabetic rats. Both parameters normalized after 15 days of vanadate treatment, whereas insulin administration (60 h) raised L-pyruvate kinase mRNA three-fold above control values. Oral treatment for 15 days with vanadate can thus mimic the effect of insulin on both pyruvate kinase and 6-phosphofructo-2-kinase/fructose-2,6- bisphosphatase in livers of diabetic rats.
Miralpeix
M
M
Departament de Ciències Fisiològiques, Universitat de Barcelona, Spain.
Carballo
E
E
Bartrons
R
R
Crepin
K
K
Hue
L
L
Rousseau
G G
GG
D000284:Administration, Oral; D000818:Animals; D001786:Blood Glucose / Q000378:metabolism; D003600:Cytosol / Q000201:enzymology; D003921:Diabetes Mellitus, Experimental / Q000201:enzymology* / Q000235:genetics; D007118:Immunoassay; D007527:Isoenzymes / Q000235:genetics / Q000378:metabolism; D008099:Liver / Q000187:drug effects / Q000201:enzymology*; D008297:Male; D025481:Phosphofructokinase-2; D010770:Phosphotransferases / Q000235:genetics / Q000378:metabolism*; D011770:Pyruvate Kinase / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D012016:Reference Values; D014638:Vanadates / Q000008:administration & dosage / Q000494:pharmacology*
D001786:Blood Glucose; D007527:Isoenzymes; D012333:RNA, Messenger; D014638:Vanadates; D010770:Phosphotransferases; D025481:Phosphofructokinase-2; D011770:Pyruvate Kinase