title: Renal potassium handling during states of low aldosterone bio-activity: a method to differentiate renal and non-renal causes.
abstract: The purpose of this study was to examine renal potassium handling in patients with low aldosterone bio-activity. The patients with a normal renal response to aldosterone were identified by finding both a low plasma aldosterone concentration during hyperkalaemia and a transtubular potassium concentration gradient (TTKG) in the cortical distal nephron of 6 or greater within 4 h after the administration of a physiologic dose of mineralocorticoid hormone. In contrast, patients with a primary renal potassium excretion defect represent a heterogeneous population. In some, the TTKG rose when a pharmacologic but not a physiologic dose of mineralocorticoid was given; others had little renal response to the administration of this hormone. Furthermore, this renal response may be delayed and require more than 24 h to become manifest.
authors.affiliation: Department of Medicine, St. Michael's Hospital, University of Toronto, Canada.
authors.forename: R M
authors.initials: RM
authors.lastname: Zettle
authors.forename: M L
authors.initials: ML
authors.lastname: West
authors.forename: R G
authors.initials: RG
authors.lastname: Josse
authors.forename: R M
authors.initials: RM
authors.lastname: Richardson
authors.forename: P A
authors.initials: PA
authors.lastname: Marsden
authors.forename: M L
authors.initials: ML
authors.lastname: Halperin
mesh_terms: D000307:Adrenal Gland Diseases / Q000150:complications / Q000503:physiopathology*; D000324:Adrenocorticotropic Hormone; D000328:Adult; D000450:Aldosterone / Q000097:blood / Q000172:deficiency*; D003907:Dexamethasone; D005260:Female; D005438:Fludrocortisone; D006801:Humans; D006854:Hydrocortisone / Q000097:blood; D007037:Hypothyroidism / Q000150:complications / Q000503:physiopathology; D007668:Kidney / Q000503:physiopathology*; D008297:Male; D011188:Potassium / Q000378:metabolism*; D012083:Renin / Q000097:blood
chemical_list: D000450:Aldosterone; D003907:Dexamethasone; D000324:Adrenocorticotropic Hormone; D012083:Renin; D011188:Potassium; D005438:Fludrocortisone; D006854:Hydrocortisone