Mechanisms by which water and solutes are transported across cell membranes have been studied both experimentally and with mathematical models for decades. Tools of molecular and structural biology now make it possible to study specific transporters and channels, and thus identify more precisely mechanisms and possible sites of activity. This in turn permits the test of hypotheses based on in-vitro experiments, molecular structure and function with models of the whole organ.
In this talk we describe two mathematical tools, and how they serve to increase our understanding in renal physiology. We first describe neural net models used to characterize integral membrane proteins. Secondly, we show how a model of the rat kidney is used to incorporate information obtained in vitro and at the molecular level to test a hypothesis about regulation of urine formation by the mammalian kidney.