title: The fractal spatial distribution of pancreatic islets in three dimensions: a self-avoiding growth model.
abstract: The islets of Langerhans, responsible for controlling blood glucose levels, are dispersed within the pancreas. A universal power law governing the fractal spatial distribution of islets in two-dimensional pancreatic sections has been reported. However, the fractal geometry in the actual three-dimensional pancreas volume, and the developmental process that gives rise to such a self-similar structure, has not been investigated. Here, we examined the three-dimensional spatial distribution of islets in intact mouse pancreata using optical projection tomography and found a power law with a fractal dimension of 2.1. Furthermore, based on two-dimensional pancreatic sections of human autopsies, we found that the distribution of human islets also follows a universal power law with a fractal dimension of 1.5 in adult pancreata, which agrees with the value previously reported in smaller mammalian pancreas sections. Finally, we developed a self-avoiding growth model for the development of the islet distribution and found that the fractal nature of the spatial islet distribution may be associated with the self-avoidance in the branching process of vascularization in the pancreas.
authors: Laboratory of Biological Modeling, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, USA.
authors: Junghyo
authors: J
authors: Jo
authors: Andreas
authors: A
authors: Hörnblad
authors: German
authors: G
authors: Kilimnik
authors: Manami
authors: M
authors: Hara
authors: Ulf
authors: U
authors: Ahlgren
authors: Vipul
authors: V
authors: Periwal
mesh_terms: D000328:Adult; D000818:Animals; D005260:Female; D017709:Fractals; D006801:Humans; D007515:Islets of Langerhans / Q000033:anatomy & histology / Q000254:growth & development*; D051379:Mice; D008810:Mice, Inbred C57BL; D008953:Models, Anatomic; D008954:Models, Biological; D041622:Tomography, Optical
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