title: Muscle contractile properties in severely burned rats.
abstract: Burn induces a sustained catabolic response which causes massive loss of muscle mass after injury. A better understanding of the dynamics of muscle wasting and its impact on muscle function is necessary for the development of effective treatments. Male Sprague-Dawley rats underwent either a 40% total body surface area (TBSA) scald burn or sham burn, and were further assigned to subgroups at four time points after injury (days 3, 7, 14 and 21). In situ isometric contractile properties were measured including twitch tension (Pt), tetanic tension (Po) and fatigue properties. Body weight decreased in burn and sham groups through day 3, however, body weight in the sham groups recovered and increased over time compared to burned groups, which progressively decreased until day 21 after injury. Significant differences in muscle wet weight and protein weight were found between sham and burn. Significant differences in muscle contractile properties were found at day 14 with lower absolute Po as well as specific Po in burned rats compared to sham. After burn, the muscle twitch tension was significantly higher than the sham at day 21. No significant difference in fatigue properties was found between the groups. This study demonstrates dynamics of muscle atrophy and muscle contractile properties after severe burn; this understanding will aid in the development of approaches designed to reduce the rate and extent of burn induced muscle loss and function.
authors.affiliation: US Army Institute of Surgical Research, 3400 Rawley E Chambers Ave, Fort Sam Houston, San Antonio, TX 78234-6315, USA. xiaowu.wu@amedd.army.mil
authors.forename: Xiaowu
authors.initials: X
authors.lastname: Wu
authors.forename: Steven E
authors.initials: SE
authors.lastname: Wolf
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Walters
mesh_terms: D000818:Animals; D001835:Body Weight; D002056:Burns / Q000378:metabolism / Q000503:physiopathology*; D004195:Disease Models, Animal; D007537:Isometric Contraction / Q000502:physiology; D008297:Male; D009119:Muscle Contraction / Q000502:physiology*; D018763:Muscle Fatigue / Q000502:physiology; D018482:Muscle, Skeletal / Q000473:pathology / Q000502:physiology*; D009133:Muscular Atrophy / Q000503:physiopathology; D051381:Rats; D017207:Rats, Sprague-Dawley; D013997:Time Factors
references.citation: Lancet. 1999 Nov 20;354(9192):1789
references.pmid: 10577644
references.citation: J Appl Physiol (1985). 1997 Jan;82(1):182-8
references.pmid: 9029214
references.citation: Plast Reconstr Surg. 2006 Jan;117(1):152-64
references.pmid: 16404262
references.citation: J Trauma. 1968 Nov;8(6):1049-51
references.pmid: 5722120
references.citation: J Appl Physiol (1985). 1991 Nov;71(5):1921-8
references.pmid: 1761492
references.citation: J Trauma. 1981 Jun;21(6):417-23
references.pmid: 7230293
references.citation: Dig Dis Sci. 2000 Feb;45(2):415-20
references.pmid: 10711461
references.citation: Muscle Nerve. 2005 May;31(5):610-20
references.pmid: 15779020
references.citation: J Surg Res. 1978 Nov;25(5):394-403
references.pmid: 713539
references.citation: Am J Physiol. 1990 Jun;258(6 Pt 1):C1031-5
references.pmid: 2360618
references.citation: J Trauma. 1987 Mar;27(3):262-6
references.pmid: 3104621
references.citation: J Burn Care Rehabil. 1995 Jul-Aug;16(4):445-50; discussion 444
references.pmid: 8582926
references.citation: J Appl Physiol Respir Environ Exerc Physiol. 1979 Aug;47(2):435-9
references.pmid: 468702
references.citation: J Appl Physiol (1985). 1989 Jun;66(6):2739-49
references.pmid: 2745338
references.citation: BMJ. 2004 Aug 7;329(7461):343-5
references.pmid: 15297346
references.citation: New Horiz. 1993 May;1(2):348-52
references.pmid: 7922414
references.citation: Burns. 1995 Sep;21(6):415-21
references.pmid: 8554681
references.citation: J Trauma. 1997 Apr;42(4):635-40
references.pmid: 9137250
references.citation: J Am Coll Surg. 1995 Jan;180(1):33-42
references.pmid: 8000653
references.citation: Shock. 2002 Dec;18(6):518-22
references.pmid: 12462559
references.citation: J Gerontol A Biol Sci Med Sci. 2001 Oct;56(10):B443-8
references.pmid: 11584029
references.citation: Apoptosis. 2009 Jan;14(1):52-65
references.pmid: 19009350
references.citation: Ann Surg. 1973 Aug;178(2):215-7
references.pmid: 4198796
references.citation: Physiol Rev. 1994 Jan;74(1):49-94
references.pmid: 8295935
references.citation: J Burn Care Rehabil. 1995 Sep-Oct;16(5):539-42
references.pmid: 8537428
references.citation: Int J Mol Med. 1998 Jan;1(1):163-9
references.pmid: 9852215
references.citation: J Physiol. 1979 Nov;296:453-69
references.pmid: 160929
references.citation: Am J Occup Ther. 1989 Jan;43(1):17-24
references.pmid: 2923171
references.citation: Plast Reconstr Surg. 1987 Jun;79(6):927-34
references.pmid: 3588732
references.citation: Surgery. 2000 Aug;128(2):312-9
references.pmid: 10923010
references.citation: J Burn Care Rehabil. 1990 Sep-Oct;11(5):400-4
references.pmid: 2246309
references.citation: Metabolism. 1989 Jul;38(7):634-40
references.pmid: 2661965
references.citation: J Surg Res. 1998 Apr;76(1):11-6
references.pmid: 9695731
references.citation: Histochem Cell Biol. 1999 Feb;111(2):117-23
references.pmid: 10090572
references.citation: Arch Surg. 2000 Dec;135(12):1432-42
references.pmid: 11115349
references.citation: J Physiol. 1973 Nov;234(3):723-48
references.pmid: 4148752
references.citation: J Appl Physiol (1985). 1996 Jan;80(1):261-70
references.pmid: 8847313