1. Intercalated cells are involved in K+ secretion in the collecting duct.
Intercalated cells are involved in K+secretion in the collecting duct. This cartoon illustrates the location of the voltage-dendent renal outer medullary small-conductance K+ (ROMK) and the flow-dependent big potassium (BK) channels in the intercalated cells (type A-IC and type B-IC) and principal cells. (A) Under normal dietary conditions, ROMK predominantly secretes K+. However, under the influence of a K+-rich diet, because of the increased activity of the basolateral Na+/K+-ATPase, the transport via the epithelial sodium channel (ENaC)– transport increases, generating a driving force for ROMK to secrete more K+ from the principal cells. (B) When high K+ secretion is accompanied by increased flow, it stimulates BK channel synthesis and function in the intercalated cells (type A-IC and type B-IC).
Ankita Roy et al. CJASN 2015;10:
©2015 by American Society of Nephrology