Renal collecting duct

The **renal collecting duct** is the terminal segment of the nephron in the kidney, extending from the distal convoluted tubule through the cortex and medulla to the renal pelvis. It comprises multiple segments (connecting tubule, cortical collecting duct, medullary collecting duct, papillary duct) and consists of two main cell types: principal cells and intercalated cells[1][2][3][5][7][9]. - Principal cells regulate water and sodium reabsorption under hormonal control, primarily via vasopressin (antidiuretic hormone) and aldosterone, using proteins such as aquaporin-2 and epithelial sodium channel (ENaC)[4]. - Intercalated cells help regulate acid-base balance by secreting or absorbing hydrogen and bicarbonate ions[3][5]. The collecting duct is essential in the kidney's final adjustment of urine composition and volume. It is not itself a molecular drug target but contains cells expressing key therapeutic protein targets (e.g., vasopressin V2 receptor, aquaporin-2, ENaC) that are relevant in diseases like nephrogenic diabetes insipidus and some forms of hypertension[4]. In rare cases, it is the site of origin of collecting duct carcinoma, an aggressive type of kidney cancer[6][8]. In summary, the "renal collecting duct" is an **anatomical and functional structure rather than a specific drug or biomarker target**. It is not appropriate as a canonical molecular therapeutic target.

Other names

Collecting ductDuct of Bellini (for distal segment)Papillary duct