ABSTRACT
Through a process of filtration, secretion, and absorption, the kidney regulates the excretion of waste and retention of solutes such as electrolytes and amino acids. In processing the blood the kidney also functions to maintain acid-base homeostasis, plasma osmolality, and blood pressure. These functional roles of the kidney are the basis for the recent interest in developing in vitro kidney models that can be applied to drug development, disease studies, and nephrotoxicity testing.
