The thiazide-sensitive Na–Cl cotransporter is an aldosterone-induced protein

• DOI: 10.1073/pnas.95.24.14552
• Publication Date: 2002-07-26T14:42:40Z
• Authors: Gheun-Ho Kim; Shyama Masilamani; Rachel Turner; Carter Mitchell; James B. Wade; Mark A. Knepper
• Keywords: Distal convoluted tubule; Mineralocorticoid; Renal cortex; Apical membrane; Renal medulla

Although the collecting duct is regarded as primary site at which mineralocorticoids regulate renal sodium transport in kidney, recent evidence points to distal convoluted tubule a possible of mineralocorticoid action. To investigate whether expression thiazide-sensitive Na–Cl cotransporter (TSC), chief apical entry pathway cells, we prepared an affinity-purified, peptide-directed antibody TSC. On immunoblots, recognized prominent 165-kDa band membrane fractions from cortex but not medulla. Immunofluorescence immunocytochemistry showed TSC labeling only cells. Semiquantitative immunoblotting studies demonstrated large increase rats on low-NaCl diet (207 ± 21% control diet). localization tissue sections confirmed strong expression. Treatment for 10 days with continuous subcutaneous infusion aldosterone also increased (380 58% controls). Furthermore, 7-day treatment orally administered mineralocorticoid, fludrocortisone, (656 114% We conclude that important action aldosterone, strongly up-regulates