title: Achilles tendinosis: a morphometrical study in a rat model.
abstract: This study addresses the morphopathogenesis of Achilles tendinosis, using a rat model and presenting quantitative analysis of time-dependent histological changes. Thirty Wistar rats were used, randomly split in experimental and control groups. Animals of the experimental group were submitted to a treadmill running scheme. Five animals of each group were euthanized at four, eight and sixteen weeks. Achilles tendons were collected and processed routinely for histopath sections. Slides were stained by Hematoxylin-Eosin, Picrosirius Red, Alcian Blue, AgNOR, TUNEL and evaluated morphometrically. Cellular density decreased slightly along the time and was higher in the experimental group than in controls at fourth, eighth and sixteenth weeks. Fiber microtearing, percentual of reticular fibers and glycosaminoglycans content increased along the time and were higher in experimental group than in controls at all-time intervals. AgNOR labeling here interpreted as a marker of transcription activity was higher in the experimental groups than in controls at all-time intervals. Apoptotic cells were more frequent and diffusely distributed in tendinosis samples than in control groups. These results suggest that as mechanical overload is becoming chronic, cellular turnover and matrix deposition increases leading to tendinosis. The combination of staining techniques and morphometry used here to describe the evolution of lesions occurring in a rat model system has proved to be suited for the study of induced Achilles tendinosis.
authors.affiliation: Departament of General Pathology, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil.
authors.forename: Rafael Duarte
authors.initials: RD
authors.lastname: Silva
authors.forename: Mark Anthony
authors.initials: MA
authors.lastname: Glazebrook
authors.forename: Vinicius Castro
authors.initials: VC
authors.lastname: Campos
authors.forename: Anilton Cesar
authors.initials: AC
authors.lastname: Vasconcelos
mesh_terms: D000125:Achilles Tendon / Q000293:injuries / Q000378:metabolism / Q000473:pathology*; D000818:Animals; D017209:Apoptosis; D003094:Collagen / Q000378:metabolism; D012090:Cumulative Trauma Disorders / Q000378:metabolism / Q000473:pathology*; D004195:Disease Models, Animal; D006025:Glycosaminoglycans / Q000378:metabolism; D020287:In Situ Nick-End Labeling; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D012420:Running; D013194:Staining and Labeling; D052256:Tendinopathy / Q000378:metabolism / Q000473:pathology*; D013708:Tendon Injuries / Q000378:metabolism / Q000473:pathology*; D013997:Time Factors
chemical_list: D006025:Glycosaminoglycans; D003094:Collagen
references.citation: J Orthop Res. 2004 Mar;22(2):334-8
references.pmid: 15013093
references.citation: Am J Sports Med. 2005 Apr;33(4):561-7
references.pmid: 15722279
references.citation: Br J Sports Med. 2002 Aug;36(4):239-49
references.pmid: 12145112
references.citation: Histochem J. 1986 Jan;18(1):5-14
references.pmid: 2423479
references.citation: Science. 1997 May 30;276(5317):1345-6
references.pmid: 9190676
references.citation: J Orthop Res. 2008 Jun;26(6):840-6
references.pmid: 18183626
references.citation: Sports Med. 2004;34(14):1005-17
references.pmid: 15571430
references.citation: Arthroscopy. 1998 Nov-Dec;14(8):840-3
references.pmid: 9848596
references.citation: Arthritis Rheum. 2007 Mar;56(3):871-81
references.pmid: 17328060
references.citation: Int J Exp Pathol. 2007 Aug;88(4):217-26
references.pmid: 17696902
references.citation: Physiol Rev. 2004 Apr;84(2):649-98
references.pmid: 15044685
references.citation: Acta Cir Bras. 2009 Jul-Aug;24(4):282-9
references.pmid: 19705026
references.citation: J Cell Biol. 1992 Nov;119(3):493-501
references.pmid: 1400587
references.citation: Clin J Sport Med. 2007 Mar;17(2):129-34
references.pmid: 17414481
references.citation: Matrix Biol. 2001 Jun;20(3):159-69
references.pmid: 11420148
references.citation: J Shoulder Elbow Surg. 2000 Mar-Apr;9(2):79-84
references.pmid: 10810684
references.citation: Disabil Rehabil. 2008;30(20-22):1530-41
references.pmid: 18608372
references.citation: Eur J Appl Physiol. 2003 Nov;90(5-6):549-53
references.pmid: 12905044
references.citation: Annu Rev Physiol. 1997;59:575-99
references.pmid: 9074778
references.citation: Br J Sports Med. 2007 Apr;41(4):232-40
references.pmid: 17127722
references.citation: J Orthop Res. 2005 Sep;23(5):1199-205
references.pmid: 16140201
references.citation: Clin Orthop Relat Res. 2006 Feb;443:320-32
references.pmid: 16462458
references.citation: Arthritis Rheum. 2006 Mar;54(3):832-42
references.pmid: 16508964
references.citation: Am J Sports Med. 2000 Jul-Aug;28(4):499-505
references.pmid: 10921640
references.citation: Am J Sports Med. 2007 Apr;35(4):605-11
references.pmid: 17244903
references.citation: J Neurophysiol. 2005 Jun;93(6):3127-45
references.pmid: 15647397
references.citation: Clin Sports Med. 2003 Oct;22(4):675-92
references.pmid: 14560540
references.citation: Ann Biomed Eng. 2004 Mar;32(3):336-41
references.pmid: 15095808
references.citation: J Shoulder Elbow Surg. 2005 Sep-Oct;14(5):535-41
references.pmid: 16194748
references.citation: Biomaterials. 2004 Apr;25(9):1715-22
references.pmid: 14697872
references.citation: Ann Rheum Dis. 1996 Feb;55(2):109-15
references.pmid: 8712860
references.citation: J Orthop Res. 2006 Jan;24(1):80-6
references.pmid: 16419972
references.citation: Histochem J. 1979 Jul;11(4):447-55
references.pmid: 91593
references.citation: J Appl Physiol (1985). 2002 Jan;92(1):362-71
references.pmid: 11744679
references.citation: J Orthop Res. 2005 Sep;23(5):1219-25
references.pmid: 16140203
references.citation: Sports Med. 1999 Jun;27(6):393-408
references.pmid: 10418074