So, under dehydrating conditions, that is, when the volume of water inside the blood plasma of our body is low, what happens is our body releases these hormones. It releases ADH and aldosterone, and these hormones act on our collecting dog to basically make it permeable to water. Now, the mechanism by which these two hormones actually act are different. So let's discuss how each one of these hormones affects the functionality of our collecting duct. And let's begin with ADH. So, ADH, or antiduretic hormone, essentially stimulates the epithelial cells found along our collecting dust to produce membrane protein channels known as aquaporeans.