OBO_REL:part_of (UNDECLARED) renal tubule renal principal cell A cuboidal epithelial cell of the kidney which regulates sodium and potassium balance. The activity of sodium and potassium channels on the cells apical membrane is regulated by aldosterone and vasopressin. In mammals these cells are located in the renal collecting ducts. CL:0005009 TAO:0005322 teleost_anatomy columnar/cuboidal epithelial cell