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Otto Froehlich, PhD

Associate Professor of Physiology


(404) 727-7417




     My general area of interest deals with substrate transport across biological membranes. I have in the past studied the kinetics of anion and urea transport in erythrocytes and demonstrated that the urea transporter is a channel rather than a carrier-type transporter. More recently we have focused on the urea transporter in the kidney and its regulation. There are two UT genes in the mammalian genome. UT-B is expressed mainly in red blood cells and blood vessels, particularly also in the vasa recta of the renal medulla, and UT-A is expressed mainly in the kidney in several different splicing variants.

    Current research is directed towards understanding the regulatory mechanisms that cause the UT-A1 variant to transfer into the apical membrane of the inner medullary collecting duct and increase the urea permeability in response of the hormone vasopressin. Our main system is the UT-A-expressing MDCK cell line developed by my collaborators Robert Gunn and Jeff Sands. This cell line is the ideal system to study trans-epithelial urea flux and its regulation by vasopressin and the different components of if its intracellular signaling pathways. The current emphasis is on how the cAMP transient that is elicited by vasopressin determines the extent of the induced urea permeability.

Publications (PubMed)