The Interaction of Transport and Metabolism on Brain Glucose Utilization: A Reevaluation of the Lumped Constant |
| |
| Authors: | Paul D. Crane William M. Pardridge Leon D. Braun Anthony M. Nyerges William H. Oldendorf |
| |
| Affiliation: | Veterans Administration Medical Center, Brentwood, Los Angeles;und School of Medicine, Departments of Neurology und Medicine, University of California, Los Angeles, California, U.S.A. |
| |
| Abstract: | ![]()
Abstract: The relative cerebral cortical metabolism of glucose (GLU) and 2-deoxy-D-glucose (DG) was measured in vivo in control and insulin-treated hypoglycemic rats. The ratio of the utilization rate constants for the two hexoses, i.e., K DG/ K CLU is defined as the Hexose Utilization Index (HUI). The HUI was found to be invariant in rats whose cerebral glucose content exceeded 1 μmo1.g−1 wet weight (HUI = 0.48 ± 0.07). Severe hypoglycemia (plasma glucose <2 mM) effected a shift in the HUI to 1.04 ± 0.21. The results are consistent with a model in which the interpretation of the HUI is determined by the rate of transport into brain, or subsequent phosphorylation, as the rate-limiting step for hexose utilization. |
| |
| Keywords: | Brain glucose Glucose transport Glucose utilization Lumped constant Deoxyglucose Hypoglycemia |
|
|
