The goal of this project is to combine experimental and mathematical modeling techniques to investigate aspects of the renal transport and dynamics in the Munich-Wistar rat and kangaroo rat kidneys. In many rodent kidneys, the renal pelvic walls undergo peristaltic contractions, which cause bolus flow down the papillary collecting duct. The project will use immunohistochemical and videomicroscopy techniques to investigate the impacts of peristaltic contractions on medullary architecture and maximal urine concentration. Pelvic wall peristalsis generates complex fluid dynamics and likely has a substantial impact on water and solute transport in the loops of Henle, collecting ducts and blood vessels. Thus, mathematical models will be developed to simulate how the interactions between the collecting duct epithelium and the traveling bolus change tubular fluid composition in the face of peristaltic waves. The fluid-structure interactions will be modeled as an immersed boundary problem, and an accurate numerical method will be developed for the axissymmetric cylindrical coordinates.
This project will use mathematical analysis and computational techniques to answer a number of basic and important questions in renal physiology: How do the peristaltic contractions of the renal papilla impact the concentrating mechanism of the kidney? How do the anatomic differences between the kangaroo rat and the laboratory rat lead to the ability of the kangaroo rat to produce urine that is twice as concentrated? The answers to those questions are crucial in gaining an overall understanding of kidney functions.
