Question

Insertion of aquaporins in tubular epithelial cells results from the actions of _____on the_____:

Group of answer choices

renin, adrenal cortex

norepinephrine, loop of Henle

angiotensin, vascular smooth muscle

vasopressin (ADH), collecting ducts

aldosterone, proximal tubule

Answer 1

Vesopressin (ADH), collecting ducts

The the membrane of the collecting duct is practically impermeable to water. Therefore in order for water reabsorption from this part of nephron to occur it is vital that aquaporins are inserted. This is the role of vasopressin. These channels are always present on the basolateral membrane of the epithelial cells but their presence and concentration on the apicle membrane is reliant on the concentration of vasopressin in the blood. Vasopressin Works By binding to to V2 receptors on the basolateral membranes of the cells and activates adenyl cyclase creating cyclicAMP(cAMP) this intern activates protein kinase A which causes protein phosphorylation. Which causes protein phosphorylation. This causes vesicle with readymade glycoprotein AQP2 aquaporins in their membranes To move to apical cell membrane and insert the aquaporins via exocytosis. This rapidly increases the water permeability and allowing reabsorption.