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THE INFLUENCE OF PLASMA PROTEIN ON THE CHLORIDE CONTENT OF THE CEREBROSPINAL FLUID
1Laboratory for Surgical Research and the Department of Biochemistry, Harvard Medical School, Boston.
The Journal of Experimental Medicine
|October 30, 2009
Summary
Lowering plasma protein in dogs via plasmapheresis equalizes plasma and cerebrospinal fluid chloride and sodium concentrations. This supports the theory of cerebrospinal fluid as a dialysate across the choroid plexus.
Area of Science:
- Physiology
- Neuroscience
- Biochemistry
Background:
- The cerebrospinal fluid (CSF) maintains a specific ionic composition distinct from plasma.
- Plasma proteins play a role in regulating the distribution of ions between plasma and CSF.
- The choroid plexus is the primary site for CSF production and regulates its composition.
Purpose of the Study:
- To investigate the effect of reduced plasma protein on ion concentrations in plasma and CSF.
- To test the hypothesis that CSF acts as a dialysate influenced by plasma protein levels.
Main Methods:
- Plasmapheresis was performed on dogs to reduce plasma protein levels.
- Concentrations of chloride and sodium were measured in both plasma and cerebrospinal fluid.
Main Results:
- A significant reduction in the disparity of chloride and sodium concentrations between plasma and CSF was observed after plasmapheresis.
- In normal conditions, a usual disparity in ion concentrations exists, which diminishes upon protein reduction.
Conclusions:
- The findings support the theory that cerebrospinal fluid functions as a dialysate.
- The choroid plexus acts as a simple dialyzing membrane, with plasma protein influencing its selective permeability.
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