Category: transport
Nephron sequence: proximal tubule (PT) reabsorbs ~67% of filtered Na+ via Na+/H+ exchange + co-transport (the SGLT2 site for glucose — empagliflozin / dapagliflozin / canagliflozin targets here; also carbonic anhydrase, acetazolamide target). Thick ascending limb of Henle (TAL): NKCC2 (Na/K/2Cl cotransporter) — FUROSEMIDE / bumetanide / torsemide target. Distal convoluted tubule (DCT): NCC (Na/Cl cotransporter) — THIAZIDE diuretics target. Cortical collecting duct (CCD): ENaC (epithelial sodium channel) — amiloride + triamterene block directly; SPIRONOLACTONE + eplerenone block upstream mineralocorticoid receptor → reduced ENaC expression. Net diuretic potency: SGLT2i < CA-i < thiazide < loop; K-sparing reduces K+ wasting that the others produce.