Abstract
An indicator dilution technique with 22Na+ as the intravascular marker was used to measure unidirectional transport of d-[6-3H]glucose from blood into the isolated, perfused dog brain. 18 compounds which are structurally related to glucose were tested for their ability to inhibit glucose transport. The data suggest that no single hydroxyl group is absolutely required for glucose transport, but rather that glucose binding to the carrier probably occurs through hydrogen bonding at several sites (hydroxyls on carbons 1, 3, 4 and 6). In addition, α-d-glucose has higher affinity for the carrier than does β-d-glucose. A separate series of experiments demonstrated that phlorizin and phloretin are competitive inhibitors of glucose transport into brain; however, phloretin is partially competitive and inhibits at lower concentrations than does phlorizin. Inhibition by phlorizin and phloretin is mutually competitive, indicating that these compounds compete for binding to the glucose carrier. Comparison with the results reported in the literature for similar studies using the human erythrocyte demonstrates a fundamental similarity between glucose transport systems in the blood-brain barrier and erythrocyte.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 505-515 |
| Number of pages | 11 |
| Journal | BBA - Biomembranes |
| Volume | 406 |
| Issue number | 4 |
| DOIs | |
| State | Published - Nov 3 1975 |
Bibliographical note
Funding Information:The authors thank Dr W. W. Cleland for the use of computer programs used in fitting kinetic equations and gratefully acknowledge the technical assistance of Mr Paul Conway, Mr James Fitzpatrick, Mr Wilbert Heiman, Mr Bruce Levin, Mr Alton Mitmoen, Mr Bill Patterson, Miss Karla Raab, Mr Mark Saffitz, and Mrs Susan Zimbric. This investigation was supported by Grants NS05961 and 6M01932 from the National Institutes of Health and by University Surgical Associates. A. L. Betz is the recipient of a Medical Scientist Training Program award.