Collective Phenomena in Kidney Autoregulation

By controlling the excretion of water and salts, the kidneys play an important role in regulating the blood pressure and maintaining a proper environment for the cells of the body. This control depends to a large extent on mechanisms that are associated with the individual functional unit, the nephron. However, a variety of cooperative phenomena arising through interactions between the nephrons may also be important. We present experimental evidence for a coupling between nephrons that are connected via a common piece of afferent arteriole. We also develop a mathematical model that can account for the observed synchronization phenomena, and discuss the possible physiological significance of these phenomena. We are particularly interested in synchronization effects that can occur among neighboring nephrons that individually display irregular (or chaotic) dynamics in their pressure and flow regulation.