Cl-HCO3 exchange in choroid plexus: analysis by the DMO method for cell pH
( UC)DMO distribution was used to measure steady-state intracellular pH (pHi) and (HCO3)i in adult rat choroid plexus (CP) incubated in synthetic cerebrospinal fluid (CSF) for 30 min. In controls at 37 degrees C, mean pHi (6.95 at PCO2 = 30 mmHg) was close to corresponding in vivo values; and (HCO3)i/(HCO3)csf, i.e., rHCO3, was 0.37. At normal (HCO3)csf = 18 mM, cell HCO3 was accumulated threefold above electrochemical equilibrium. (HCO3)i decreased proportionally with (HCO3)csf, as the latter was altered from 47 to 9 mM; in severe extracellular acidosis (( HCO3)csf = 3.7 mM), (HCO3)i was not reduced further and so rHCO3 rose to 0.66. Except in low (HCO3)csf, acetazolamide and ouabain (10(-4) M) caused small depletion of cell HCO3. 4-Acetamido-4'-isothiocyanatostilbene-2,2'-disulfonic acid lowered (HCO3)i by 60%, thus decreasing rHCO3 (0.16) and rCl (0.25) to values close to estimated equilibrium distribution (0.15). Augmented PCO2 associated with temperature reduction to 15 degrees C elevated (HCO3)i, thereby increasing rHCO3 (to 0.66) as well as rCl. Anion distribution ratios indicate heteroanion exchange in mammalian CP.
- Research Organization:
- Univ. of Utah School of Medicine, Salt Lake City
- OSTI ID:
- 6082359
- Journal Information:
- Am. J. Physiol.; (United States), Journal Name: Am. J. Physiol.; (United States)
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
BLOOD VESSELS
HOMEOSTASIS
PH VALUE
CARBON 14 COMPOUNDS
TISSUE DISTRIBUTION
ACID CARBONATES
AMIDES
BLOOD PRESSURE
BRAIN
CEREBROSPINAL FLUID
CHLORIDES
INULIN
OUABAIN
RATS
ANIMALS
BIOLOGICAL MATERIALS
BODY
BODY FLUIDS
CARBOHYDRATES
CARDIAC GLYCOSIDES
CARDIOTONICS
CARDIOVASCULAR AGENTS
CARDIOVASCULAR SYSTEM
CENTRAL NERVOUS SYSTEM
CHLORINE COMPOUNDS
DISTRIBUTION
DRUGS
GLYCOSIDES
HALIDES
HALOGEN COMPOUNDS
LABELLED COMPOUNDS
MAMMALS
MATERIALS
NERVOUS SYSTEM
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANS
POLYSACCHARIDES
RODENTS
SACCHARIDES
STROPHANTHINS
VERTEBRATES
551001* - Physiological Systems- Tracer Techniques