Acidic amino acid clearance from CSF in the neonatal versus adult rat using ventriculo-cisternal perfusion
| Autor: | Hameed Al-Sarraf, Jane E. Preston, Malcolm B. Segal |
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| Rok vydání: | 2000 |
| Předmět: |
Male
medicine.medical_specialty Aging Biology Blood–brain barrier Biochemistry Cerebral Ventricles Cellular and Molecular Neuroscience chemistry.chemical_compound Excitatory synapse Cerebrospinal fluid Internal medicine Cisterna Magna medicine Animals Amino Acids Rats Wistar Neurotransmitter Cerebrospinal Fluid chemistry.chemical_classification Ventriculo cisternal perfusion Glutamate receptor Brain Hydrogen-Ion Concentration Amino acid Rats Perfusion Endocrinology medicine.anatomical_structure chemistry Animals Newborn Female |
| Zdroj: | Journal of neurochemistry. 74(2) |
| ISSN: | 0022-3042 |
| Popis: | The acidic amino acids aspartate and glutamate are excitatory neurotransmitters in the CNS. The clearance of this group of amino acids from CSF of adult and neonatal (7-day-old) rats was investigated. Ventriculo-cisternal perfusions with 14C-amino acids and 3H-dextran were carried out for up to 90 min. Uptake of the amino acids by the whole brain was measured, and the loss to blood was calculated. 3H-Dextran was included in the perfusate for measurement of CSF secretion rate. After 90-min perfusion, both aspartate and glutamate showed a similar uptake into the whole brain, and this did not change with age (p>0.05). However, clearance from CSF was greater in the adult, as was entry into blood from CSF. Addition of 5 mM excess unlabelled amino acid resulted in reduction in the brain uptake of both 14C-amino acids in the adult rat. In the neonate, addition of aspartate also reduced brain aspartate uptake, whereas addition of glutamate increased brain neonatal [14C]glutamate uptake. The rate of CSF secretion was significantly greater in the adult, 1.26+/-0.18 microl x min(-1) x g(-1), than in the neonate, 0.62+/-0.08 microl x min(-1) x g(-1), and the turnover of CSF was greater in adults (p |
| Databáze: | OpenAIRE |
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