Rana esculenta L. liver Fru-1,6-P2ase and G-6-Pase activity and Fru-2,6-P2 concentration after acclimation at 5 and 25 degrees C.
The activities of Fru-1,6-P2ase and G-6-Pase in liver and kidney of frogs acclimated at 5 and 25 degrees C and Fru-2,6-P2 level in liver were investigated. The aim of this study was to examine the effect of thermal acclimation on regulatory enzymes of gluconeogenesis and on concentration of gluconeogenesis regulator. Fru-1,6-P2ase activity in liver of frogs acclimated at 5 degrees C was 6.16 +/- 0.77 and 4.46 +/- 0.46 U/g wt in those acclimated at 25 degrees C; the respective values for G-6-Pase were 0.46 +/- 0.04 and 0.25 +/- 0.02 U/g wt. Fru-1,6-P2ase activity in kidney was 3.2 +/- 0.48 U/g wt at 5 degrees C and 2.64 +/- 0.23 U/g wt at 25 degrees C; the respective values for G-6-Pase were 0.2 +/- 0.05 and 0.17 +/- 0.05 U/g wt. K(m) of frog liver Fru-1,6-P2ase determined after acclimation at 5 degrees C and to 25 degrees C was 1.36 and 1.41 microM, respectively. Frog liver Fru-1,6-P2ase was allosterically inhibited by AMP. I0.5 determined after acclimation at 5 degrees C was 10.55 microM and after acclimation at 25 degrees C was 10.88 microM. Liver Fru-2,6-P2 concentration after acclimation at 5 degrees C was 0.44 +/- 0.13 nmol/g wt in comparison with 0.58 +/- 0.19 nmol/g wt after acclimation at 25 degrees C. In conclusion, cold exposure increased hepatic gluconeogenic capacity of Rana esculenta.
Dziewulska-Szwajkowska
D
D
Department of Animal Physiology, University of Wrocław, Poland.
Lozińska-Gabska
M
M
Dzugaj
A
A
D000064:Acclimatization / Q000502:physiology*; D000249:Adenosine Monophosphate / Q000494:pharmacology; D000494:Allosteric Regulation; D000818:Animals; D001786:Blood Glucose / Q000378:metabolism; D004791:Enzyme Inhibitors / Q000494:pharmacology; D006597:Fructose-Bisphosphatase / Q000037:antagonists & inhibitors / Q000378:metabolism*; D005635:Fructosediphosphates / Q000378:metabolism*; D005943:Gluconeogenesis; D005952:Glucose-6-Phosphatase / Q000378:metabolism*; D007668:Kidney / Q000378:metabolism; D007700:Kinetics; D008099:Liver / Q000378:metabolism; D011893:Rana esculenta / Q000378:metabolism*; D013696:Temperature
D001786:Blood Glucose; D004791:Enzyme Inhibitors; D005635:Fructosediphosphates; D000249:Adenosine Monophosphate; C027652:fructose 2,6-diphosphate; D006597:Fructose-Bisphosphatase; D005952:Glucose-6-Phosphatase