Effect of pH on Cl sup minus transport in TAL of Henle's loop

Journal Article · Tue Dec 01 00:00:00 EST 1987 · American Journal of Physiology; (USA)

OSTI ID:7191841

Kondo, Yoshiaki; Yoshitomi, Koji; Imai, Masashi ^[1]

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1. National Cardiovascular Center Research Institute, Osaka (Japan)

To further characterize the mechanism of Cl{sup {minus}} transport across the hamster thin ascending limb (TAL) of Henle's loop, the authors examined effects of pH on Cl{sup {minus}} permeability as determined by either the choline chloride diffusion voltage or the lumen-to-bath {sup 36}Cl flux in the isolated segments perfused in vitro. When pH of the bathing fluid or the perfusate was reduced from 7.4 to 5.8, the Cl{sup {minus}}-Na{sup +} permeability ratio was reduced from 2.77 {plus minus} 0.21 to 0.48 {plus minus} 0.02 or from 2.55 {plus minus} 0.15 to 0.81 {plus minus} 0.11, respectively. At 37{degree}C, when the pH of the bathing fluid was reduced from 7.4 to 6.2, the lumen-to-bath flux coefficient for {sup 36}Cl was reduced from 84.8 {plus minus} 7.5 to 20.4 {plus minus} 3.2, whereas the value for {sup 22}Na was unchanged. From the pH titration curves for P{sub Cl}/P{sub Na}, pK{sub a} values for proton binding were 6.31 and 5.78, and Hill's coefficients were 2.1 and 2.3 on the basolateral side and on the luminal side, respectively. Intracellular acidification with o-nitrophenylacetate also decreased the Cl{sup {minus}} permeability. They conclude that (1) Cl{sup {minus}} transport across the TAL is mediated by a process that is sensitive to ambient pH, (2) the basolateral side is more sensitive to pH, (3) the proton binding exhibits positive cooperativity in the modulation of Cl{sup {minus}} transport, and (4) intracellular pH might also modulate Cl{sup {minus}} transport.

• OSTI ID: 7191841
• Journal Information: American Journal of Physiology; (USA), Vol. 253:6; ISSN 0002-9513
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
CHLORINE 36
MEMBRANE TRANSPORT
PH VALUE
BIOLOGICAL EFFECTS
SODIUM 22
TUBULES
PERMEABILITY
ACIDIFICATION
HAMSTERS
PERFUSED TISSUES
PHYSIOLOGY
PROTONS
SODIUM CHLORIDES
ALKALI METAL COMPOUNDS
ALKALI METAL ISOTOPES
ANIMAL TISSUES
ANIMALS
BARYONS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BETA-PLUS DECAY RADIOISOTOPES
BODY
CHLORIDES
CHLORINE COMPOUNDS
CHLORINE ISOTOPES
ELECTRON CAPTURE RADIOISOTOPES
ELEMENTARY PARTICLES
FERMIONS
HADRONS
HALIDES
HALOGEN COMPOUNDS
ISOMERIC TRANSITION ISOTOPES
ISOTOPES
KIDNEYS
LIGHT NUCLEI
MAMMALS
NUCLEI
NUCLEONS
ODD-ODD NUCLEI
ORGANS
RADIOISOTOPES
RODENTS
SODIUM COMPOUNDS
SODIUM ISOTOPES
TISSUES
VERTEBRATES
YEARS LIVING RADIOISOTOPES
550201* - Biochemistry- Tracer Techniques