The focus of the Satlin lab is on defining the mechanisms leading to the acquisition, maintenance and regulation of transepithelial transport in the mammalian cortical collecting duct, a nephron segment responsible in the adult for the final renal regulation of total body K+ and Na+ homeostasis. Specifically, her lab continues to expand on two major discoveries: (1) unique developmental programs underlying the postnatal expression of ion channels responsible for Na absorption (ENaC) and K secretion (SK/ROMK and BK channels) in this epithelium, thus establishing the physiological basis for total body Na and K retention required for somatic growth and maintenance of blood pressure, and (2) the role of variations in urinary flow rate (i.e., hydrodynamic forces) in mechanoregulation of renal epithelial ion channels in health and disease. Recent efforts have been devoted to developing model systems, including 3D bioprinted collecting ducts and human PSC-derived kidney organoids, which recapitulate ion transport and signaling phenotypes of the in vivo distal nephron. As the lab serves as a national "single nephron physiology" Core of an NIH-funded O'Brien Center for Kidney Research, the techniques available to lab members and external investigators include in vitro microperfusion of single nephron segments, fluorescent functional imaging of single cells in native tissue (for measurement of cell pH, calcium, K+ and Na+), patch clamp studies of single cells for analysis of channel activity, and molecular techniques (real time PCR, immunoblotting) applied to single cells and tubules.