Mark Terasaki, Ph.D., Jason Cory Brunson, Ph.D., Kristina Suarez, Brandon Causing, Ryan Elkind
The blood supply is filtered of excess and waste in capillary tufts called glomeruli, the main components of kidney nephrons. Most kidney disease is caused by obstruction or destruction of glomerular vessels, so glomerular structure is important to renal pathology. Recent developments in serial-section scanning electron microscopy and virtual reality have reduced the cost of reconstructing glomerular networks, and we have used spatial graph models to gain insight into their spatial and topological structure.
For example, using circuit analysis, centrality analysis, and the fundamental theorem of calculus, we are able to trace an average blood flow through each glomerulus, forming a sort of “average” path from afferent (incoming) to efferent (outgoing) arteriole. These average paths exhibit a consistent cul-de-sac pattern, with the implication that arteriolar paths avoid direct routes between the arterioles near the vascular pole, consistent with the expectation that such “shortcuts” would allow blood to pass without filtration. They also suggest that, on average, glomeruli exhibit lateral symmetry with respect to the plane defined by the arterioles and the vascular and tubular poles. These and other properties will inform our understanding of how glomeruli function when only partially obstructed or destroyed.
Terasaki M, Brunson JC, Sardi J. Analysis of the three dimensional structure of the kidney glomerulus capillary network. Sci Rep. 2020 Nov 23;10(1):20334. doi: 10.1038/s41598-020-77211-x. PMID: 33230129; PMCID: PMC7683536.