Cellular localization of the potassium channel Kir7.1 in guinea pig and human kidney. 2001

C Derst, and J R Hirsch, and R Preisig-Müller, and E Wischmeyer, and A Karschin, and F Döring, and A Thomzig, and R W Veh, and E Schlatter, and W Kummer, and J Daut
Institut für Normale und Pathologische Physiologie, Philipps-Universität, Marburg, Germany.

BACKGROUND K(+) channels have important functions in the kidney, such as maintenance of the membrane potential, volume regulation, recirculation, and secretion of potassium ions. The aim of this study was to obtain more information on the localization and possible functional role of the inwardly rectifying K(+) channel, Kir7.1. METHODS Kir7.1 cDNA (1114 bp) was isolated from guinea pig kidney (gpKir7.1), and its tissue distribution was analyzed by reverse transcriptase-polymerase chain reaction (RT-PCR). In addition, a genomic DNA fragment (6153 bp) was isolated from a genomic library. cRNA was expressed in Xenopus laevis oocytes for functional studies. Immunohistochemistry and RT-PCR were used to localize Kir7.1 in guinea pig and human kidney. RESULTS The expression of gpKir7.1 in Xenopus laevis oocytes revealed inwardly rectifying K(+) currents. The reversal potential was strongly dependent on the extracellular K(+) concentration, shifting from -14 mV at 96 mmol/L K(+) to -90 mV at 1 mmol/L K(+). gpKir7.1 showed a low affinity for Ba(2+). Significant expression of gpKir7.1 was found in brain, kidney, and lung, but not in heart, skeletal muscle, liver, or spleen. Immunocytochemical detection in guinea pig identified the gpKir7.1 protein in the basolateral membrane of epithelial cells of the proximal tubule. RT-PCR analysis identified strong gpKir7.1 expression in the proximal tubule and weak expression in glomeruli and thick ascending limb. In isolated human tubule fragments, RT-PCR showed expression in proximal tubule and thick ascending limb. CONCLUSIONS Our results suggest that Kir7.1 may contribute to basolateral K(+) recycling in the proximal tubule and in the thick ascending limb.

UI MeSH Term Description Entries
D007687 Kidney Tubules, Proximal The renal tubule portion that extends from the BOWMAN CAPSULE in the KIDNEY CORTEX into the KIDNEY MEDULLA. The proximal tubule consists of a convoluted proximal segment in the cortex, and a distal straight segment descending into the medulla where it forms the U-shaped LOOP OF HENLE. Proximal Kidney Tubule,Proximal Renal Tubule,Kidney Tubule, Proximal,Proximal Kidney Tubules,Proximal Renal Tubules,Renal Tubule, Proximal,Renal Tubules, Proximal,Tubule, Proximal Kidney,Tubule, Proximal Renal,Tubules, Proximal Kidney,Tubules, Proximal Renal
D008138 Loop of Henle The U-shaped portion of the renal tubule in the KIDNEY MEDULLA, consisting of a descending limb and an ascending limb. It is situated between the PROXIMAL KIDNEY TUBULE and the DISTAL KIDNEY TUBULE. Ascending Limb of Loop of Henle,Descending Limb of Loop of Henle,Henle Loop
D008297 Male Males
D008564 Membrane Potentials The voltage differences across a membrane. For cellular membranes they are computed by subtracting the voltage measured outside the membrane from the voltage measured inside the membrane. They result from differences of inside versus outside concentration of potassium, sodium, chloride, and other ions across cells' or ORGANELLES membranes. For excitable cells, the resting membrane potentials range between -30 and -100 millivolts. Physical, chemical, or electrical stimuli can make a membrane potential more negative (hyperpolarization), or less negative (depolarization). Resting Potentials,Transmembrane Potentials,Delta Psi,Resting Membrane Potential,Transmembrane Electrical Potential Difference,Transmembrane Potential Difference,Difference, Transmembrane Potential,Differences, Transmembrane Potential,Membrane Potential,Membrane Potential, Resting,Membrane Potentials, Resting,Potential Difference, Transmembrane,Potential Differences, Transmembrane,Potential, Membrane,Potential, Resting,Potential, Transmembrane,Potentials, Membrane,Potentials, Resting,Potentials, Transmembrane,Resting Membrane Potentials,Resting Potential,Transmembrane Potential,Transmembrane Potential Differences
D008969 Molecular Sequence Data Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories. Sequence Data, Molecular,Molecular Sequencing Data,Data, Molecular Sequence,Data, Molecular Sequencing,Sequencing Data, Molecular
D009865 Oocytes Female germ cells derived from OOGONIA and termed OOCYTES when they enter MEIOSIS. The primary oocytes begin meiosis but are arrested at the diplotene state until OVULATION at PUBERTY to give rise to haploid secondary oocytes or ova (OVUM). Ovocytes,Oocyte,Ovocyte
D011188 Potassium An element in the alkali group of metals with an atomic symbol K, atomic number 19, and atomic weight 39.10. It is the chief cation in the intracellular fluid of muscle and other cells. Potassium ion is a strong electrolyte that plays a significant role in the regulation of fluid volume and maintenance of the WATER-ELECTROLYTE BALANCE.
D003001 Cloning, Molecular The insertion of recombinant DNA molecules from prokaryotic and/or eukaryotic sources into a replicating vehicle, such as a plasmid or virus vector, and the introduction of the resultant hybrid molecules into recipient cells without altering the viability of those cells. Molecular Cloning
D005260 Female Females
D006168 Guinea Pigs A common name used for the genus Cavia. The most common species is Cavia porcellus which is the domesticated guinea pig used for pets and biomedical research. Cavia,Cavia porcellus,Guinea Pig,Pig, Guinea,Pigs, Guinea

Related Publications

C Derst, and J R Hirsch, and R Preisig-Müller, and E Wischmeyer, and A Karschin, and F Döring, and A Thomzig, and R W Veh, and E Schlatter, and W Kummer, and J Daut
July 2003, Investigative ophthalmology & visual science,
C Derst, and J R Hirsch, and R Preisig-Müller, and E Wischmeyer, and A Karschin, and F Döring, and A Thomzig, and R W Veh, and E Schlatter, and W Kummer, and J Daut
November 2000, Journal of the American Society of Nephrology : JASN,
C Derst, and J R Hirsch, and R Preisig-Müller, and E Wischmeyer, and A Karschin, and F Döring, and A Thomzig, and R W Veh, and E Schlatter, and W Kummer, and J Daut
October 2021, The Journal of general physiology,
C Derst, and J R Hirsch, and R Preisig-Müller, and E Wischmeyer, and A Karschin, and F Döring, and A Thomzig, and R W Veh, and E Schlatter, and W Kummer, and J Daut
February 2008, American journal of physiology. Cell physiology,
C Derst, and J R Hirsch, and R Preisig-Müller, and E Wischmeyer, and A Karschin, and F Döring, and A Thomzig, and R W Veh, and E Schlatter, and W Kummer, and J Daut
December 1989, British journal of pharmacology,
C Derst, and J R Hirsch, and R Preisig-Müller, and E Wischmeyer, and A Karschin, and F Döring, and A Thomzig, and R W Veh, and E Schlatter, and W Kummer, and J Daut
October 2000, FEBS letters,
C Derst, and J R Hirsch, and R Preisig-Müller, and E Wischmeyer, and A Karschin, and F Döring, and A Thomzig, and R W Veh, and E Schlatter, and W Kummer, and J Daut
March 2006, Cell biology international,
C Derst, and J R Hirsch, and R Preisig-Müller, and E Wischmeyer, and A Karschin, and F Döring, and A Thomzig, and R W Veh, and E Schlatter, and W Kummer, and J Daut
June 1996, The Journal of pharmacy and pharmacology,
C Derst, and J R Hirsch, and R Preisig-Müller, and E Wischmeyer, and A Karschin, and F Döring, and A Thomzig, and R W Veh, and E Schlatter, and W Kummer, and J Daut
January 2007, American journal of physiology. Renal physiology,
C Derst, and J R Hirsch, and R Preisig-Müller, and E Wischmeyer, and A Karschin, and F Döring, and A Thomzig, and R W Veh, and E Schlatter, and W Kummer, and J Daut
March 1965, The Journal of general physiology,
Copied contents to your clipboard!