Streptozotocin-induced diabetes influences the activity of ecto-nucleoside triphosphate diphosphohydrolase 1 of rat osseous plate membranes.
We report the kinetic characterization of an ecto-nucleosidetriphosphate diphosphohydrolase 1 from rat osseous plate membranes in streptozotocin-induced diabetic rats, which arises during ectopic mineralization twenty days after a subcutaneous implantation of demineralized bone matrix, Insulin deficiency decreased the ecto-nucleoside triphosphate diphosphohydrolase activity from 1293.1 +/- 39.8 (control rats) to 556.0 +/- 8.2 nmol Pi/(min mg). Two families of ATP hydrolyzing sites showed cooperative effects with specific activities of 256.2 +/- 7.7 nmol Pi/(min mg) and 299.8 +/- 8.9 nmol Pi/(min mg), and studies on the stimulation of the enzyme by magnesium and calcium ions showed that the decrease in enzyme activity results from changes in the affinity of the enzyme for these ions. To our knowledge this is the first study associating the effects of type I diabetes with an ecto-nucleoside triphosphate diphosphohydrolase activity from rat osseous plate membranes.
Rezende
Adriana A
AA
Departamento de Química, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, 14040-901 Ribeirão Preto, Brazil.
Petenusci
Sergio O
SO
Furriel
Rosa P M
RP
Leone
Francisco A
FA
D000251:Adenosine Triphosphatases / Q000378:metabolism*; D000818:Animals; D002118:Calcium / Q000494:pharmacology; D003921:Diabetes Mellitus, Experimental / Q000378:metabolism*; D006132:Growth Plate / Q000201:enzymology*; D007328:Insulin / Q000172:deficiency; D007700:Kinetics; D008274:Magnesium / Q000494:pharmacology; D008297:Male; D051381:Rats; D017208:Rats, Wistar
D007328:Insulin; D000251:Adenosine Triphosphatases; D008274:Magnesium; D002118:Calcium