Rather water diffuses from the collecting duct into the interstitial fluids, through the aquaporins. The fusion of the aquaporins with the membrane lining of the collecting duct ( due to synthesis of the ADH by the hypothalamic neurone and and it releases into the blood from the post. pituitary gland) increases the permeability of the collecting duct to water. Therefore water moves into the interstitial fluids from the collecting duct by osmosis, leading to production of more concentrated urine is produced .
