Physiology 3120 Lecture Notes - Lecture 4: Distal Convoluted Tubule, Aldosterone, Sodium Channel
25 Feb 2017
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65% of the filtrate is reabsorbed here. Main things reabsorbed: glucose (100%, amino acids, ions (k+, cl-, na+, ca2+, water. Located on the basolateral side of membrane of all tubule. Important in maintaining ion concentration within cells (na+ = low; k+ = high) Na+ conc drives the reabsorption of majority of ions. Allow glucose to move out of cell down its concentration gradient most of aa are reabsorbed via this symporter) Na+ has a favourable gradient; aa does not. Allow aa to move out of cell down its concentration. 20 aa symporter has to recognize all of them (simplified; Bicarbonate is another ion that"s filtered in the capsular gradient. Important in balancing the ph of blood space & reabsorbed (bc it is an important buffer) Reabsorbed via this exchanger: bicarbonate binds with h, forms co2 and h2o, co2 is easily absorbed (small non-polar molecule) Expressed on the luminal and basal side of membrane.
