Properties of a Cl(-)-conductive pathway(s) in microsomes from rat kidney inner medulla. Involvement of cystic fibrosis transmembrane regulator protein.
The properties of a protein-kinase-A(PKA)-activated Cl(-)-conductive pathway(s) in alkaline phosphatase-enriched microsomes from the rat inner medulla (IMV) were investigated. Transcripts of cystic fibrosis transmembrane regulator (CFTR) were detected by reverse transcription/polymerase analysis of total RNA from the inner medulla, while immunoblot analysis using anti-CFTR antibodies detected a 170-kDa protein in the IMV. The PKA Cl(-)-conductive pathway(s) was studied by measuring the rate of valinomycin-induced microsomal swelling by light scattering. PKA increased the rate of valinomycin-induced swelling of vesicles consistent with the presence of Cl(-)-conductive pathway(s). The pharmacological properties and anion selectivity of the PKA-activated Cl(-)-conductive pathway(s) were similar to those of the CFTR Cl(-) channel. Our results show that a CFTR Cl(-) channel and possibly another cAMP-activated pathway(s) may participate in Cl(-) secretion in the rat inner medulla.
Benharouga
M
M
Inserm U.323, CHU Necker, Paris, France.
Lipecka
J
J
Fanen
P
P
Baudoin-Legros
M
M
Banting
G
G
Fritsch
J
J
Edelman
A
A
D017878:4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid / Q000494:pharmacology; D000818:Animals; D000838:Anions; D001483:Base Sequence; D015415:Biomarkers; D018118:Chloride Channels / Q000096:biosynthesis / Q000737:chemistry / Q000502:physiology*; D017868:Cyclic AMP-Dependent Protein Kinases / Q000378:metabolism; D019005:Cystic Fibrosis Transmembrane Conductance Regulator / Q000096:biosynthesis / Q000737:chemistry / Q000502:physiology*; D017931:DNA Primers; D007425:Intracellular Membranes / Q000502:physiology; D007679:Kidney Medulla / Q000502:physiology*; D007700:Kinetics; D008297:Male; D008861:Microsomes / Q000187:drug effects / Q000502:physiology*; D008969:Molecular Sequence Data; D010539:Permeability; D016133:Polymerase Chain Reaction; D051381:Rats; D017208:Rats, Wistar; D014634:Valinomycin / Q000494:pharmacology
D000838:Anions; D015415:Biomarkers; D018118:Chloride Channels; D017931:DNA Primers; D019005:Cystic Fibrosis Transmembrane Conductance Regulator; D014634:Valinomycin; D017868:Cyclic AMP-Dependent Protein Kinases; D017878:4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid