A compartmental analysis of24Na kinetics in rat cerebrum, sciatic nerve and cerebrospinal fluid
- 1 August 1972
- journal article
- Published by Wiley in The Journal of Physiology
- Vol. 224 (3), 559-581
- https://doi.org/10.1113/jphysiol.1972.sp009913
Abstract
1. The kinetics of (24)Na exchange in rat cerebrospinal fluid, brain and sciatic nerve were studied during steady-state plasma isotope conditions. The entrance of (24)Na into brain and sciatic nerve was found to fit a three compartmental model. Using newly derived equations for compartmental analysis, the first compartment (24)Na space of brain was found to be about 22% and the second compartment space about 6%; the corresponding sciatic nerve spaces were 26 and 11%, respectively. In the discussion, arguments are presented that suggest that the first compartment is the extracellular space (ECS) and the second compartment is the intracellular space. The t((1/2)) for compartmental equilibration between plasma and brain ECS was 2 hr and from ECS to intracellular space 14 hr; in nerve the respective t((1/2))'s were (2/3) hr and 10 hr.2. A third compartment of 18% was found in sciatic nerve which was interpreted to be anatomically confined to the epi- and perineurium; in brain the corresponding space was 2% and was felt to be anatomically and kinetically an inactive closed compartment in parallel with the blood.3. There were two t((1/2))'s for plasma-c.s.f. (24)Na equilibration of less than 10 min and 2 hr.4. Profiles of brain, from cortex to ventricle, at 6 min, demonstrated a gradient of decreasing (24)Na radioactivity from ventricle to cortex.Keywords
This publication has 24 references indexed in Scilit:
- Physiological studies on the development of obstructive hydrocephalus in the monkeyNeurology, 1971
- Extracellular space of the cerebral cortex of normothermic and hypothermic catsExperimental Neurology, 1970
- Blood vessels and tissue space associated with the brain of the ratJournal of Anatomy, 1969
- JUNCTIONS BETWEEN INTIMATELY APPOSED CELL MEMBRANES IN THE VERTEBRATE BRAINThe Journal of cell biology, 1969
- Sodium movement across the blood-brain barrier in newborn and adult rats and its autoradiographic localizationBrain Research, 1968
- Determination of calcium, copper, iron, magnesium, manganese, potassium, sodium, zinc, and chloride concentrations in several brain areasAnalytical Biochemistry, 1967
- The permeability of mouse cerebral capillaries to sodiumLife Sciences, 1967
- FINE STRUCTURAL LOCALIZATION OF A BLOOD-BRAIN BARRIER TO EXOGENOUS PEROXIDASEThe Journal of cell biology, 1967
- The entry of Na24 from blood into the brain of mice during 30 minutes after intravenous isotope injectionLife Sciences, 1967
- KINETICS OF ION MOVEMENT IN THE SQUID GIANT AXONThe Journal of general physiology, 1955