Gluconeogenesis during hypoxia in vascular smooth muscle studied by 13C-NMR.
We investigated whether hypoxia altered the utilization of fructose-1,6-bisphosphate as a gluconeogenic or glycolytic intermediate in superfused media from hog carotid artery. Using 13C-NMR, we found that although 3-13C-lactate production from 1-13C-glucose increased compared to that under well-oxygenated conditions, the conversion of exogenously applied 1,6-13C-fructose-1,6-bisphosphate to glucose (gluconeogenesis) or to 3-13C-lactate was not significantly affected by hypoxia. Since hypoxia alters the rate of glucose conversion to lactate but not the conversion of fructose-1,6-bisphosphate to glucose, we conclude that glycolysis and glycogenolysis may continue to be compartmentalized during hypoxia and that a high rate of gluconeogenesis can occur even during hypoxia.
Hardin
C D
CD
Department of Physiology, University of Missouri, Columbia, USA.
Roberts
T M
TM
D000818:Animals; D002339:Carotid Arteries / Q000378:metabolism; D005635:Fructosediphosphates / Q000378:metabolism; D005943:Gluconeogenesis; D005947:Glucose / Q000378:metabolism; D006019:Glycolysis; D000860:Hypoxia / Q000378:metabolism*; D066298:In Vitro Techniques; D019344:Lactic Acid / Q000378:metabolism; D009682:Magnetic Resonance Spectroscopy; D009131:Muscle, Smooth, Vascular / Q000378:metabolism*; D010101:Oxygen Consumption; D013552:Swine
D005635:Fructosediphosphates; D019344:Lactic Acid; D005947:Glucose; C029063:fructose-1,6-diphosphate