title: A potential mechanism for allometric trabecular bone scaling in terrestrial mammals.
abstract: Trabecular bone microstructural parameters, including trabecular thickness, spacing, and number, have been reported to scale with animal size with negative allometry, whereas bone volume fraction is animal size-invariant in terrestrial mammals. As for the majority of scaling patterns described in animals, its underlying mechanism is unknown. However, it has also been found that osteocyte density is inversely related to animal size, possibly adapted to metabolic rate, which shows a negative relationship as well. In addition, the signalling reach of osteocytes is limited by the extent of the lacuno-canalicular network, depending on trabecular dimensions and thus also on animal size. Here we propose animal size-dependent variations in osteocyte density and their signalling influence distance as a potential mechanism for negative allometric trabecular bone scaling in terrestrial mammals. Using an established and tested computational model of bone modelling and remodelling, we run simulations with different osteocyte densities and influence distances mimicking six terrestrial mammals covering a large range of body masses. Simulated trabecular structures revealed negative allometric scaling for trabecular thickness, spacing, and number, constant bone volume fraction, and bone turnover rates inversely related to animal size. These results are in agreement with previous observations supporting our proposal of osteocyte density and influence distance variation as a potential mechanism for negative allometric trabecular bone scaling in terrestrial mammals. The inverse relationship between bone turnover rates and animal size further indicates that trabecular bone scaling may be linked to metabolic rather than mechanical adaptations.
authors: Orthopaedic Biomechanics, Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, The Netherlands.
authors: Patrik
authors: P
authors: Christen
authors: Keita
authors: K
authors: Ito
authors: Bert
authors: B
authors: van Rietbergen
mesh_terms: D000818:Animals; D001835:Body Weight / Q000502:physiology; D001842:Bone and Bones / Q000033:anatomy & histology* / Q000502:physiology*; D020342:Finite Element Analysis; D008322:Mammals / Q000033:anatomy & histology* / Q000502:physiology*; D008954:Models, Biological; D010011:Osteocytes / Q000166:cytology; D010012:Osteogenesis / Q000502:physiology; D013314:Stress, Mechanical
keywords: bone modelling and remodelling; computational modelling and simulation; metabolic rate; micro-finite element analysis; osteocyte density; osteocyte influence distance; trabecular bone scaling
references: J Biomech. 2005 Apr;38(4):931-41
references: 15713314
references: J Bone Miner Res. 2007 Oct;22(10):1557-70
references: 17605631
references: Bone. 2010 Feb;46(2):314-21
references: 19733269
references: Nature. 2000 Jun 8;405(6787):704-6
references: 10864330
references: Arch Oral Biol. 2012 Sep;57(9):1274-81
references: 22480456
references: Science. 1990 Nov 23;250(4984):1097-103
references: 2251499
references: Science. 1989 Jul 7;245(4913):45-8
references: 2740914
references: FASEB J. 1995 Mar;9(5):441-5
references: 7896017
references: Anat Rec (Hoboken). 2013 Feb;296(2):210-26
references: 23355518
references: J Hum Evol. 2006 Dec;51(6):591-602
references: 16963108
references: Bone. 2011 Dec;49(6):1340-50
references: 21964411
references: PLoS One. 2013 Apr 24;8(4):e62172
references: 23637993
references: Bone. 2009 Aug;45(2):321-9
references: 19398046
references: J Cell Sci. 2011 Apr 1;124(Pt 7):991-8
references: 21402872
references: Bone. 2008 Feb;42(2):250-9
references: 18063436
references: J Orthop Res. 1996 Nov;14(6):972-9
references: 8982141
references: J Exp Biol. 2000 Sep;203(Pt 18):2737-45
references: 10952874
references: Biomech Model Mechanobiol. 2015 Apr;14 (2):427-32
references: 24952222
references: Proc Biol Sci. 2011 Oct 22;278(1721):3067-73
references: 21389033
references: J Biomech. 2012 Sep 21;45(14):2411-6
references: 22883080
references: Calcif Tissue Int. 1990 Jul;47(1):35-9
references: 2369689
references: Nat Commun. 2014 Sep 11;5:4855
references: 25209333
references: J Exp Biol. 1998 Feb;201(Pt 4):573-90
references: 9438832
references: Bone. 2014 Mar;60:172-85
references: 24334189
references: J Orthop Res. 1995 Jul;13(4):503-12
references: 7674066
references: Biomech Model Mechanobiol. 2012 Mar;11(3-4):483-92
references: 21735242
references: Proc Biol Sci. 2013 Mar 13;280(1758):20130172
references: 23486443
references: Curr Osteoporos Rep. 2012 Jun;10(2):118-25
references: 22552701
references: Eur Cell Mater. 2012 Sep 24;24:278-91
references: 23007912
references: J Bone Miner Res. 2008 Sep;23(9):1353-68
references: 18505374
references: Science. 1976 Nov 12;194(4266):732-4
references: 982039
references: Am J Phys Anthropol. 2009 Mar;138(3):318-32
references: 18785633
references: Anat Rec. 1987 Sep;219(1):1-9
references: 3688455
references: J Biomech. 1988;21(2):131-9
references: 3350827
references: J Bone Miner Res. 2011 Feb;26(2):277-85
references: 20715178
references: Bone. 2011 Dec;49(6):1141-51
references: 21893221
references: Biochem Biophys Res Commun. 1995 Dec 14;217(2):640-8
references: 7503746
references: J Struct Biol. 2013 Aug;183(2):123-31
references: 23639903
references: J Bone Miner Res. 2012 Aug;27(8):1784-93
references: 22431329