Effects of inhibitors on chloride outflux from CSF
The regulation of the CSF (Cl/sup -/) plays a key role in CNS acid-base homeostasis. The authors have shown in previous studies that chloride influx from blood to CSF is largely dependent upon sodium-coupled carrier mediated movement. Therefore, the mechanism of chloride outflux from CSF to brain was evaluated in anesthetized dogs using ventricular-cisternal perfusion (VCP) with the short-lived isotope /sup 38/Cl/sup -/ and dextran. The outflux of /sup 38/Cl/sup -/ from CSF was determined from the different movements between /sup 38/Cl/sup -/ and dextran using a one compartment model. VCP was performed at a rate of 1.4 ml/min for 14 min, and then slowed to 0.28 ml/min. The /sup 38/Cl/sup -/ activity decreased to a steady state level about 12% lower than that of dextran within 40-50 minutes. Under control conditions (19 runs in 7 dogs), the rate of chloride outflux was 0.059 +/- 0.004 min/sup -1/ (mean +/- SE). It was not significantly changed after the inclusion of bumetanide (10/sup -5/ molar) in the VCP fluid (n=6), which inhibits sodium-coupled Cl/sup -/ transport, or with acetazolamide 4.5 x 10/sup -3/ molar (n=4) which inhibits carbonic anhydrase. The authors conclude that chloride outflux from CSF is not dependent upon sodium-coupled carrier mediated movement, which is in contrast with chloride influx from blood to CSF, nor is it dependent upon carbonic anhydrase activity.
- Research Organization:
- Massachusetts General Hospital, Boston
- OSTI ID:
- 6859667
- Report Number(s):
- CONF-8604222-; TRN: 87-010325
- Journal Information:
- Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States), Vol. 45:4; Conference: 70. annual meeting of the Federation of American Society for Experimental Biology, St. Louis, MO, USA, 13 Apr 1986
- Country of Publication:
- United States
- Language:
- English
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CENTRAL NERVOUS SYSTEM
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CHLORIDES
MEMBRANE TRANSPORT
BIOLOGICAL MODELS
BRAIN
CARBONIC ANHYDRASE
CHLORINE 38
DEXTRAN
DOGS
RESPONSE MODIFYING FACTORS
ANIMALS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BLOOD SUBSTITUTES
BODY
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CARBON-OXYGEN LYASES
CHLORINE COMPOUNDS
CHLORINE ISOTOPES
DRUGS
ENZYMES
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HYDRO-LYASES
ISOMERIC TRANSITION ISOTOPES
ISOTOPES
LIGHT NUCLEI
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NERVOUS SYSTEM
NUCLEI
ODD-ODD NUCLEI
ORGANIC COMPOUNDS
ORGANS
POLYSACCHARIDES
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SECONDS LIVING RADIOISOTOPES
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550201* - Biochemistry- Tracer Techniques