Metabolic clearance of insulin from the cerebrospinal fluid in the anesthetized rat
- Laboratoire d'etude du Metabolisme Azote, Ceyrat (France)
Infusion of 125I-(Tyr A14)-insulin at tracer doses into the cerebrospinal fluid (CSF) resulted in a slow rate of increase in the CSF-labeled insulin during the first 2 hours with a plateau thereafter. Labeled insulin was cleared from the CSF at a higher rate than 3H-inulin, a marker of CSF bulk flow. The labeled insulin was mainly distributed in all the ventricular and periventricular brain regions. Small amounts of degraded insulin appeared in the CSF. Coinfusion with an excess of unlabeled insulin impaired the clearance and degradation of labeled insulin. It also inhibited the labeling in medial hypothalamus, olfactory bulbs and brain stem. In contrast, coinfusion of ribonuclease B (used to test the specificity of uptake) was without any effect. It was concluded that there is an active insulin intake from CSF into brain specific compartments that is presumably essential for the effects of insulin on brain function.
- OSTI ID:
- 6726830
- Journal Information:
- Peptides (Fayetteville, New York); (USA), Vol. 11:1; ISSN 0196-9781
- Country of Publication:
- United States
- Language:
- English
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BRAIN
BIOLOGICAL FUNCTIONS
INSULIN
METABOLISM
BIOLOGICAL MARKERS
CEREBROSPINAL FLUID
CLEARANCE
INULIN
IODINE 125
RATS
RECEPTORS
SCINTILLATION COUNTING
TRACER TECHNIQUES
TRITIUM COMPOUNDS
ANIMALS
BETA DECAY RADIOISOTOPES
BIOLOGICAL MATERIALS
BODY
BODY FLUIDS
CARBOHYDRATES
CENTRAL NERVOUS SYSTEM
COUNTING TECHNIQUES
DAYS LIVING RADIOISOTOPES
ELECTRON CAPTURE RADIOISOTOPES
FUNCTIONS
HORMONES
HYDROGEN COMPOUNDS
INTERMEDIATE MASS NUCLEI
IODINE ISOTOPES
ISOTOPE APPLICATIONS
ISOTOPES
MAMMALS
MATERIALS
MEMBRANE PROTEINS
NERVOUS SYSTEM
NUCLEI
ODD-EVEN NUCLEI
ORGANIC COMPOUNDS
ORGANS
PEPTIDE HORMONES
POLYSACCHARIDES
PROTEINS
RADIOISOTOPES
RODENTS
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VERTEBRATES
550501* - Metabolism- Tracer Techniques