| First Author | Carrisoza-Gaytan R | Year | 2020 |
| Journal | JCI Insight | Volume | 5 |
| Issue | 8 | PubMed ID | 32255763 |
| Mgi Jnum | J:301810 | Mgi Id | MGI:6505368 |
| Doi | 10.1172/jci.insight.130553 | Citation | Carrisoza-Gaytan R, et al. (2020) Intercalated cell BKalpha subunit is required for flow-induced K+ secretion. JCI Insight 5(8) |
| abstractText | 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 alpha subunit (BKalpha) in ICs (IC-BKalpha-KO). Whole cell charybdotoxin-sensitive (ChTX-sensitive) K+ currents were readily detected in control ICs but largely absent in ICs of IC-BKalpha-KO mice. When placed on a high K+ (HK) diet for 13 days, blood [K+] was significantly greater in IC-BKalpha-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-BKalpha-KO CCDs of both sexes. Also, flow-stimulated epithelial Na+ channel-mediated (ENaC-mediated) Na+ absorption was greater in CCDs from female IC-BKalpha-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-BKalpha-KO mice. |
