Aquaporins

Aquaporins are water transport channel <a href="Proteins">proteins</a> to aid reabsorption. They are found most abundantly in regions involved in transporting particularly high rates of <a href="Water">water</a>, for example in the <a href="Epithelial cells">epithelial cells</a> of the collecting duct at the end of a <a href="Nephron">nephron</a> in the <a href="Kidney">kidney</a>Alberts et al.(2008)Molecular Biology of the Cell,5th Edition: p673.

The fusion of more aquaporins to the cell surface membrane is stimulated by the reception of <a href="ADH (anti-diuretic hormone)">ADH (anti-diuretic hormone)</a>, which is secreted in times of water shortage by the <a href="Posterior pituitary gland">posterior pituitary gland</a>, decreases water loss through <a href="Urine">urine</a>.