Cotransport of sodium and chloride by the adult mammalian choroid plexus

Journal Article · Thu Feb 01 04:00:00 EST 1990 · American Journal of Physiology; (USA)

OSTI ID:7027275

Johanson, C E; Sweeney, S M; Parmelee, J T; Epstein, M H ^[1]

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1. Brown Univ./Rhode Island Hospital, Providence (USA)

Cerebrospinal fluid formation stems primarily from the transport of Na and Cl in choroid plexus (CP). To characterize properties and modulation of choroidal transporters, we tested diuretics and other agents for ability to alter ion transport in vitro. Adult Sprague-Dawley rats were the source of CPs preincubated with drug for 20 min and then transferred to cerebrospinal fluid (CSF) medium containing 22Na or 36Cl with (3H)mannitol (extracellular correction). Complete base-line curves were established for cellular uptake of Na and Cl at 37 degrees C. The half-maximal uptake occurred at 12 s, so it was used to assess drug effects on rate of transport (nmol Na or Cl/mg CP). Bumetanide (10(-5) and 10(-4) M) decreased uptake of Na and Cl with maximal inhibition (up to 45%) at 10(-5) M. Another cotransport inhibitor, furosemide (10(-4) M), reduced transport of Na by 25% and Cl by 33%. However, acetazolamide (10(-4) M) and atriopeptin III (10(-7) M) significantly lowered uptake of Na (but not Cl), suggesting effect(s) other than on cotransport. The disulfonic stilbene 4,4'-diisothiocyanostilbene-2,2'-disulfonic acid (DIDS; 10(-4) M), known to inhibit Cl-HCO3 exchange, substantially reduced the transport of 36Cl. Bumetanide plus DIDS (both 10(-4) M) caused additive inhibition of 90% of Cl uptake, which provides strong evidence for the existence of both cotransport and antiport Cl carriers. Overall, this in vitro analysis, uncomplicated by variables of blood flow and neural tone, indicates the presence in rat CP of the cotransport of Na and Cl in addition to the established Na-H and Cl-HCO3 exchangers.

• OSTI ID: 7027275
• Journal Information: American Journal of Physiology; (USA), Journal Name: American Journal of Physiology; (USA) Vol. 258; ISSN 0002-9513; ISSN AJPHA
• Country of Publication: United States
• Language: English

Related Subjects

550201* -- Biochemistry-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
ALKALI METAL ISOTOPES
ALKALI METALS
ANIMALS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BETA-PLUS DECAY RADIOISOTOPES
BIOLOGICAL MATERIALS
BIOLOGICAL PATHWAYS
BIOSYNTHESIS
BODY FLUIDS
CEREBROSPINAL FLUID
CHEMICAL PROPERTIES
CHLORIDES
CHLORINE 36
CHLORINE COMPOUNDS
CHLORINE ISOTOPES
ELECTRON CAPTURE RADIOISOTOPES
ELEMENTS
HALIDES
HALOGEN COMPOUNDS
HYDROGEN COMPOUNDS
INHIBITION
ISOMERIC TRANSITION ISOTOPES
ISOTOPE APPLICATIONS
ISOTOPE DILUTION
ISOTOPES
LIGHT NUCLEI
MAMMALS
MATERIALS
MEMBRANE TRANSPORT
METALS
NUCLEI
ODD-ODD NUCLEI
ORGANIC COMPOUNDS
PEPTIDES
PROTEINS
RADIOISOTOPES
RATS
RODENTS
SODIUM
SODIUM 22
SODIUM ISOTOPES
SYNTHESIS
TRACER TECHNIQUES
TRITIUM COMPOUNDS
VERTEBRATES
YEARS LIVING RADIOISOTOPES