Glutamate uptake and metabolism was studied in cerebral cortical astrocytes. The expression of the astrocytic glutamate transporter GLAST was found to be stimulated by extracellular glutamate through activation of kainate receptors on the astrocytes. Energy metabolism and ammonia homeostasis are two
Glutamate metabolism in malnutrition and sepsis in man
β Scribed by Penelope A. Kingsland; A. Kingsnorth; G. T. Royle; M. G. W. Kettlewell; B. D. Ross
- Publisher
- John Wiley and Sons
- Year
- 1981
- Tongue
- English
- Weight
- 372 KB
- Volume
- 68
- Category
- Article
- ISSN
- 0007-1323
No coin nor oath required. For personal study only.
β¦ Synopsis
Summary
The metabolism of intravenous glutamate has been studied for its usefulness as a nutrient in intravenous feeding regimens. Intravenously infused monosodium Lglutamate was rapidly removed from the blood with a halflife of 10Β·7 and 9Β·1 min in healthy control and malnourished septic patients, respectively. Under the same conditions, alanine was metabolized much more slowly, with a half-life of 35 min (1). After the infusion of glutamate, blood lactate fell and glucose was increased in the control patients but not in the sick patients. Blood pyruvate, ketone bodies, glutamine, aspartate and alanine levels did not change after the infusion of glutamate in either group of patients. Increased urinary excretion of aspartate was observed in the control patients following the infusion of glutamate, but in the sick patients there was an increased excretion of glutamine. Insulin concentration in the blood rose after the infusion of glutamatein the control patients but not in the sick patients. Although the glutamate half-life was similar in thetwo groups of patients, glutamate was metabolized differently in the sick. Deamination predominates over transamination. We conclude that glutamate, in the amounts provided in intravenous feeding, is safe, although its effectiveness may be less than previously thought.
π SIMILAR VOLUMES
Glutamate levels were determined in the fasting plasma of 22 patients with early-stage primary amyotrophic lateral sclerosis (ALS) and compared to those of healthy and diseased controls. There was a significant increase (by approximately loo%, p < 0.0005) in the plasma glutamate of the ALS patients
The ability of cultured astrocytes to metabolize [U-13 C]glutamate in the absence of glucose was investigated by utilizing 13 C nuclear magnetic resonance spectroscopy to identify 13 C-labeled metabolites. Control cultures (3 mM glucose), hypoglycemic cultures (glucose-deprived), severe hypoglycemic