The following are the correct statement about vasopressin and they includes;
1. Vasopressin is capable of inducing the exocytosis of aquaporin to the apical membrane of collecting duct cells.
2. Vasopressin is capable of binding to a nuclear receptor and hence ensure an increase in the expression of aquaporin subunits genes
3. Vasopressin is capable of binding to a cell surface receptor.
The statements 1, 2 and 3 are CORRECT.
Water excretion by the kidneys is regulated by the hormone vasopressin. It increases the amount of solute-free water reabsorbed back into the circulation from the filtrate in the kidney tubules of the nephrons. Vasopressin binds to the nuclear receptors and increases the gene expression of aquaporin subunits. It increases the water permeability of kidney collecting duct by inducing translocation of aquaporin water channels to the plasma membrane. Aquaporins allow water to move down their osmotic gradient and out of the nephron and increase the amount of water re-absorbed from the filtrate into the bloodstream. It binds to the receptors on the cells of the collecting duct and allows water reabsorption. The functioning of the hormone is mediated by the vasopressin receptors called the tissue specific G protein-coupled receptors.
