renal chloride reabsorption renal chloride reabsorption renal reabsorption of chloride (cl−) is a part of renal physiology, in order not to lose too much chloride in the urine. overview table characteristics of cl− reabsorption characteristic proximal tubule loop of henle distal convoluted tubule collecting duct system s1 s2 s3 descending limb thin ascending limb thick ascending limb connecting tubule initial collecting tubule cortical collecting ducts medullary collecting ducts reabsorption (%) reabsorption (mmoles/day) concentration (mm)115135 electrical driving force (mv) −3+3+15−5 to +5−40 chemical driving force (mv) electrochemical driving force (mv)(positive) apical transport proteins(passively) cl-formate exchanger cl-oxalate exchanger cl−-oh− exchanger na-k-2cl cotransporter na-cl cotransporter principal cells: paracellularily basolateral transport proteins chloride channels cl-k cotransporter cl−/hco3− exchanger chloride channels chloride channels chloride channels β intercalated cells: cl−hco3− exchanger other reabsorption features