Intercalated cell BKα subunit is required for flow-induced K+ secretion.
JCI Insight
; 5(8)2020 04 07.
Article
en En
| MEDLINE
| ID: mdl-32255763
ABSTRACT
BK channels are expressed in intercalated cells (ICs) and principal cells (PCs) in the cortical collecting duct (CCD) of the mammalian kidney and have been proposed to be responsible for flow-induced K+ secretion (FIKS) and K+ adaptation. To examine the IC-specific role of BK channels, we generated a mouse with targeted disruption of the pore-forming BK α subunit (BKα) in ICs (IC-BKα-KO). Whole cell charybdotoxin-sensitive (ChTX-sensitive) K+ currents were readily detected in control ICs but largely absent in ICs of IC-BKα-KO mice. When placed on a high K+ (HK) diet for 13 days, blood [K+] was significantly greater in IC-BKα-KO mice versus controls in males only, although urinary K+ excretion rates following isotonic volume expansion were similar in males and females. FIKS was present in microperfused CCDs isolated from controls but was absent in IC-BKα-KO CCDs of both sexes. Also, flow-stimulated epithelial Na+ channel-mediated (ENaC-mediated) Na+ absorption was greater in CCDs from female IC-BKα-KO mice than in CCDs from males. Our results confirm a critical role of IC BK channels in FIKS. Sex contributes to the capacity for adaptation to a HK diet in IC-BKα-KO mice.
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Banco de datos:
MEDLINE
Asunto principal:
Potasio
/
Subunidades alfa de los Canales de Potasio de Gran Conductancia Activados por Calcio
/
Túbulos Renales Colectores
Límite:
Animals
Idioma:
En
Revista:
JCI Insight
Año:
2020
Tipo del documento:
Article
País de afiliación:
Estados Unidos