Enhancement of glucose transport in rat thymocytes by different radical sources.
This study demonstrates that oxidative stress induced in rat thymocytes by the hydrophilic 2,2'-azobis(2-amidinopropane)dihydrochloride (AAPH), the lipophilic cumene hydroperoxide (CumOOH) and the freely diffusible H2O2 is associated with an activation of facilitative glucose transport rate, mediated by GLUT1, the major transporter in this cell type. We compared the effects of the three tested radical sources on the kinetic transport parameters, showing that the transport rate enhancement in the treated cells can be ascribed to an increase in the Vmax value, apart from the site of generation of the oxidative stress. The enhancement of glucose transport by the three oxidants in thymocytes was significantly attenuated both by protein tyrosine kinase inhibitors as genistein and tyrphostin A23 and by U73122, a phospholipase C inhibitor. Genistein and U73122 reversed also the cited increase of Vmax values. It is concluded that the stimulation of glucose transport in response to different oxidants is mediated, at least in part, through reactive oxygen species (ROS)-induced stimulation of protein tyrosine kinase and phospholipase C pathways.
Hakim
Gabriele
G
Dipartimento di Biochimica G. Moruzzi Università di Bologna, Via Irnerio, 48, I-40126 Bologna, Italy. hakim@biocfarm.unibo.it
Fiorentini
Diana
D
Maraldi
Tullia
T
Landi
Laura
L
D000818:Animals; D001692:Biological Transport; D015153:Blotting, Western; D002462:Cell Membrane / Q000378:metabolism; D002470:Cell Survival; D004591:Electrophoresis, Polyacrylamide Gel; D004791:Enzyme Inhibitors / Q000494:pharmacology; D004963:Estrenes / Q000494:pharmacology; D005609:Free Radicals; D019833:Genistein / Q000494:pharmacology; D005947:Glucose; D006861:Hydrogen Peroxide / Q000494:pharmacology; D007700:Kinetics; D008297:Male; D010084:Oxidation-Reduction; D011505:Protein-Tyrosine Kinases / Q000378:metabolism; D011760:Pyrrolidinones / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D017382:Reactive Oxygen Species; D013950:Thymus Gland / Q000166:cytology; D013997:Time Factors; D010738:Type C Phospholipases / Q000378:metabolism / Q000502:physiology; D020032:Tyrphostins / Q000494:pharmacology
D004791:Enzyme Inhibitors; D004963:Estrenes; D005609:Free Radicals; D011760:Pyrrolidinones; D017382:Reactive Oxygen Species; D020032:Tyrphostins; C060229:1-(6-((3-methoxyestra-1,3,5(10)-trien-17-yl)amino)hexyl)-1H-pyrrole-2,5-dione; D006861:Hydrogen Peroxide; D019833:Genistein; D011505:Protein-Tyrosine Kinases; D010738:Type C Phospholipases; D005947:Glucose; C060641:tyrphostin A23