Bone is functionally impaired in dystrophic mice but less so than skeletal muscle.
The primary purpose of this study was to determine if tibial bone strength is compromised in dystrophic mice and if so, what geometric and material properties contribute. Results of three-point bending tests showed that tibia of mdx and dko (dystrophin- and utrophin-deficient) mice had up to 50% lower strength and stiffness compared to wild-type mice. Micro-computed tomography indicated that dystrophic tibia had reductions of 6-57% in cortical cross-sectional moment of inertia and cross-sectional area. Metaphyseal trabecular bone morphometry was also altered up to 78% in dystrophic mice. Bone-to-muscle functional ratios (i.e., three-point bending measures:muscle strength) indicated that bone strength was relatively high in 7-week-old dystrophic mice compared to muscle strength, but ratios were similar to wild-type mice by 24 months of age. Young dystrophic mice have compromised bone strength; these models may be useful for designing therapeutic regimens aimed at improving the skeleton.
Department of Kinesiology, University of Minnesota, Minneapolis, MN 55455, USA. golne003@umn.edu
Susan A
SA
Novotny
Gordon L
GL
Warren
Angela S
AS
Lin
Robert E
RE
Guldberg
Kristen A
KA
Baltgalvis
Dawn A
DA
Lowe
D000367:Age Factors; D000704:Analysis of Variance; D000818:Animals; D015519:Bone Density; D001847:Bone Diseases / Q000209:etiology* / Q000235:genetics; D001842:Bone and Bones / Q000473:pathology / Q000503:physiopathology; D004195:Disease Models, Animal; D016189:Dystrophin / Q000235:genetics / Q000378:metabolism*; D005260:Female; D005838:Genotype; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018101:Mice, Inbred mdx; D018345:Mice, Knockout; D053580:Muscle Strength / Q000502:physiology; D018482:Muscle, Skeletal / Q000473:pathology*; D020388:Muscular Dystrophy, Duchenne / Q000150:complications* / Q000235:genetics / Q000473:pathology*; D013314:Stress, Mechanical; D049411:Utrophin / Q000172:deficiency
D016189:Dystrophin; D049411:Utrophin
J Appl Physiol (1985). 1994 Sep;77(3):1421-30
7836148
J Appl Physiol (1985). 1996 May;80(5):1660-5
8727552
Osteoporos Int. 2003 Sep;14(9):761-7
12897980
Bone. 2009 Feb;44(2):214-24
19022418
Exp Gerontol. 2005 Dec;40(12):966-75
16243468
Bone. 1996 Jul;19(1):55-9
8830989
J Electromyogr Kinesiol. 2009 Jun;19(3):e180-6
17977021
Bone. 1993 Jul-Aug;14(4):625-34
8274305
Arch Phys Med Rehabil. 2005 Feb;86(2):284-8
15706555
J Biomech. 1997 Nov-Dec;30(11-12):1101-6
9456377
J Cell Sci. 1994 Jun;107 ( Pt 6):1477-83
7962191
Arch Biochem Biophys. 1961 May;93:440-7
13786180
J Muscle Res Cell Motil. 1999 Oct;20(7):605-25
10672510
Muscle Nerve. 2008 Oct;38(4):1290-303
18816601
J Physiol. 2001 Sep 1;535(Pt 2):591-600
11533147
Anat Rec A Discov Mol Cell Evol Biol. 2003 Dec;275(2):1081-101
14613308
Dev Med Child Neurol. 2002 Oct;44(10):695-8
12418795
Cell. 1997 Aug 22;90(4):729-38
9288752
Neuromuscul Disord. 2007 Dec;17(11-12):919-28
17627820
J Musculoskelet Neuronal Interact. 2010 Mar;10(1):25-34
20190377
Arch Phys Med Rehabil. 1993 Jul;74(7):711-5
8328892
Muscle Nerve. 2009 Sep;40(3):443-54
19618428
Anat Rec A Discov Mol Cell Evol Biol. 2005 Sep;286(1):814-22
16078270
Am J Physiol Regul Integr Comp Physiol. 2007 Nov;293(5):R2015-26
17881616
J Musculoskelet Neuronal Interact. 2008 Jan-Mar;8(1):24
18398258
J Pediatr Orthop. 2002 Mar-Apr;22(2):179-81
11856925
Proc Natl Acad Sci U S A. 1984 Feb;81(4):1189-92
6583703
J Pediatr Orthop. 2000 Jan-Feb;20(1):71-4
10641693
Clin Exp Pharmacol Physiol. 2004 Aug;31(8):485-93
15298539
J Neurol. 2009 May;256(5):768-73
19306039
FASEB J. 2007 Jul;21(9):2195-204
17360850