Cerebrospinal fluid glucose: turnover and metabolism
| Autor: | Gerald M. Hochwald, Jill Magee, Vicki Ferguson |
|---|---|
| Rok vydání: | 1985 |
| Předmět: |
medicine.medical_specialty
CSF glucose biology Chemistry Insulin medicine.medical_treatment Fissipedia Metabolism Carbohydrate biology.organism_classification Biochemistry Cellular and Molecular Neuroscience Cerebrospinal fluid Endocrinology Glucose Blood-Brain Barrier Internal medicine medicine Cats Lactates Distribution (pharmacology) Animals Carbon Radioisotopes Lactic Acid Perfusion |
| Zdroj: | Journal of neurochemistry. 44(6) |
| ISSN: | 0022-3042 |
| Popis: | The turnover of cerebrospinal fluid (CSF) glucose was studied in cats during steady-state perfusion. In all experiments, the perfusion fluid contained either tracer [14C]glucose alone or tracer glucose along with 4.45 mM unlabeled glucose. In some studies, serum glucose was lowered with insulin. The concentration of glucose and [14C]glucose in the effluent fluid was measured, and the distribution of 14C between glucose and lactate was determined by chromatography. From these values, the extraction of glucose and the metabolism of glucose to lactate were calculated. From the decrease in the specific activity of glucose in the perfusion fluid, the influx of glucose from serum was also determined. During steadystate perfusion, 71% of the radioactivity was recovered in the effluent fluid: 50% in the form of glucose, 6% in the form of lactate, and 15% in forms that were not identified. Thus, 50% of the perfusion fluid glucose was cleared, of which 29% was extracted and 21% metabolized. The influx of glucose was proportional to the serum glucose when the latter was about 2.5 mM or 10.0 mM. During perfusion with tracer glucose only, the concentration of glucose in the effluent fluid was 25% that of serum. The transport of glucose from serum was independent of the glucose concentration gradient between serum and perfusion fluid. However, when perfusion fluid glucose concentration was greater than that of serum, transport was inhibited. These studies suggest that in maintaining CSF glucose at a lower concentration than serum glucose, with equal amounts of glucose entering and leaving the CSF, 50% of CSF glucose concentration cleared is replaced by 25% of serum glucose concentration. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|
Plný text