Question

Vasopressin acts through which channels in collecting duct?

• A. Aquaporin 1
• B. Aquaporin 2
• C. GLUT –
• D. GLUT–4

Answer 1

The Correct Option is B

Vasopressin, also known as antidiuretic hormone (ADH), plays a crucial role in regulating water balance in the body. It acts on the kidneys, specifically the collecting ducts, to promote reabsorption of water.

The mechanism by which vasopressin facilitates water reabsorption involves the insertion of water channels known as aquaporins into the apical membrane of the cells lining the collecting duct. The specific type of aquaporin that vasopressin influences is Aquaporin 2.

When vasopressin binds to its receptor on the collecting duct cells, it triggers a signaling cascade involving cyclic AMP (cAMP) and protein kinase A (PKA). This cascade results in the phosphorylation and translocation of Aquaporin 2-containing vesicles to the cell membrane. Once in place, Aquaporin 2 channels increase the water permeability of the cell membrane, allowing water to be reabsorbed from the urine into the blood.

Given the options:

• Aquaporin 1
• Aquaporin 2
• GLUT –
• GLUT–4

the correct answer is Aquaporin 2 as it is the specific channel through which vasopressin exerts its effect in the collecting duct.