Expression of rat kidney anion exchanger 1 in type A intercalated cells in metabolic acidosis and alkalosis.
By enzyme-linked in situ hybridization (ISH), direct evidence is provided that acid-secreting intercalated cells (type A IC) of both the cortical and medullary collecting ducts of the rat kidney selectively express the mRNA of the kidney splice variant of anion exchanger 1 (kAE1) and no detectable levels of the erythrocyte AE1 (eAE1) mRNA. Using single-cell quantification by microphotometry of ISH enzyme reaction, medullary type A IC were found to contain twofold higher kAE1 mRNA levels compared with cortical type A IC. These differences correspond to the higher intensity of immunostaining in medullary versus cortical type A IC. Chronic changes of acid-base status induced by addition of NH(4)Cl (acidosis) or NaHCO3 (alkalosis) to the drinking water resulted in up to 35% changes of kAE1 mRNA levels in both cortical and medullary type A IC. These experiments provide direct evidence at the cellular level of kAE1 expression in type A IC and show moderate capacity of type A IC to respond to changes of acid-base status by modulation of kAE1 mRNA levels.
Huber
S
S
Institute of Anatomy, Julius-Maximilians-University of Würzburg, 97070 Würzburg, Germany.
Asan
E
E
Jöns
T
T
Kerscher
C
C
Püschel
B
B
Drenckhahn
D
D
D000138:Acidosis / Q000378:metabolism*; D000471:Alkalosis / Q000378:metabolism*; D017398:Alternative Splicing; D000643:Ammonium Chloride / Q000494:pharmacology; D000818:Animals; D017920:Antiporters / Q000032:analysis / Q000235:genetics*; D027963:Chloride-Bicarbonate Antiporters; D002712:Chlorides / Q000378:metabolism; D004912:Erythrocytes / Q000378:metabolism; D005786:Gene Expression Regulation / Q000187:drug effects; D014644:Genetic Variation; D017403:In Situ Hybridization; D007668:Kidney / Q000378:metabolism*; D007672:Kidney Cortex / Q000378:metabolism; D007679:Kidney Medulla / Q000378:metabolism; D007685:Kidney Tubules, Collecting / Q000378:metabolism; D008297:Male; D012333:RNA, Messenger / Q000235:genetics; D051381:Rats; D017208:Rats, Wistar; D017693:Sodium Bicarbonate / Q000494:pharmacology; D014158:Transcription, Genetic
D017920:Antiporters; D027963:Chloride-Bicarbonate Antiporters; D002712:Chlorides; D012333:RNA, Messenger; D000643:Ammonium Chloride; D017693:Sodium Bicarbonate