Final answer:
True, kidney cells have many aquaporins in their plasma membranes essential for water balance, facilitating water reabsorption in the nephrons and regulated by the hormone ADH.
Step-by-step explanation:
True, the plasma membranes of kidney cells are equipped with many aquaporins, which are integral proteins forming channels that facilitate the movement of water. The presence of aquaporins is crucial for maintaining water balance in the body. In the kidneys, aquaporins actively partake in the process of water reabsorption. For instance, in the descending loop of the nephron, aquaporins allow water to move freely out of the filtrate and into the surrounding interstitial fluid, thereby concentrating the urine and reabsorbing water back into the body.
Moreover, the hormone ADH (antidiuretic hormone) can regulate the insertion of aquaporins into the membranes of the collecting ducts, guiding the final amount of water reabsorbed. This hormonal regulation is key to maintaining proper fluid balance and blood pressure. In cases of diabetes or genetic mutations involving aquaporin, either excessive water loss can occur, leading to conditions like diabetes insipidus or the development of other disorders such as cataracts.