Effects of 3-mercaptopicolinic acid and a derivative of chlorogenic acid (S-3483) on hepatic and islet glucose-6-phosphatase activity.
Glucose-6-phosphatase activity was measured in hepatic microsomes and in pancreatic islets from ob/ob mice. In hepatic microsomes vanadate, phlorizin, 3-mercaptopicolinic acid and a derivative of chlorogenic acid (S-3483) inhibited the translocase activity of the enzyme, vanadate in addition inhibited hydrolase activity. In islets, vanadate inhibited both components of the enzyme, phlorizin inhibited only hydrolase activity while 3-mercaptopicolinic acid and compound S-3483 were without effect. Similarly, when islets were incubated with 3H2O and unlabeled glucose, the incorporation of 3H into medium glucose was inhibited by vanadate and phlorizin, but not by 3-mercaptopicolinic acid and S-3483. These findings suggest that, as with glucokinase, different isoenzymes of glucose-6-phosphatase are present in islets and liver.
Khan
A
A
Department of Molecular Medicine, Endocrine and Diabetes Unit, Karolinska Hospital, Stockholm, Sweden. akhtar@enk.ks.se
Ling
Z C
ZC
Pukk
K
K
Herling
A W
AW
Landau
B R
BR
Efendic
S
S
D000818:Animals; D003509:Cyclohexanecarboxylic Acids / Q000494:pharmacology*; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D005952:Glucose-6-Phosphatase / Q000037:antagonists & inhibitors / Q000378:metabolism*; D007515:Islets of Langerhans / Q000187:drug effects* / Q000201:enzymology; D051379:Mice; D008862:Microsomes, Liver / Q000187:drug effects* / Q000201:enzymology; D010695:Phlorhizin / Q000494:pharmacology; D010729:Phosphoenolpyruvate Carboxykinase (GTP) / Q000037:antagonists & inhibitors*; D010848:Picolinic Acids / Q000494:pharmacology*; D014638:Vanadates / Q000494:pharmacology
D003509:Cyclohexanecarboxylic Acids; D004791:Enzyme Inhibitors; D010848:Picolinic Acids; C113180:S 3483; D014638:Vanadates; C008363:3-mercaptopicolinic acid; D010695:Phlorhizin; D005952:Glucose-6-Phosphatase; D010729:Phosphoenolpyruvate Carboxykinase (GTP)