SOD mRNA and MDA expression in rectus femoris muscle of rats with different eccentric exercise programs and time points.
OBJECTIVE
Although superoxide dismutase (SOD) and malondialdehyde (MDA) affect Delayed Onset Muscle Soreness (DOMS), their effects are unclear in rectus femoris muscles (RFM) of rats with different eccentric exercise programs and time points. The purpose of this study is to investigate the effects of the various eccentric exercise programs at different time points on the SOD mRNA expression and MDA using rat as the animal model.


METHODS
248 male rats were randomly divided into 4 groups: control group (CTL, n = 8), once-only exercise group (OEG, n = 80), continuous exercise group (CEG, n = 80), and intermittent exercise group (IEG, n = 80). Each exercise group was divided into 10 subgroups that exercised 0.5 h, 6 h, 12 h, 24 h, 48 h, 72 h, 96 h, 120 h, 144 h, or 168 h. Rats were sacrificed and their SOD mRNA expression, and MDA concentrations of skeletal muscle tissue were measured.


RESULTS
The specimen in all eccentric exercise programs showed increased RFM SOD1 mRNA expression levels at 0.5 h (P<0.05), and decreased RFM SOD3 mRNA expression at 0.5 h (P<0.05). The continuous eccentric exercise (CE) significantly enhanced muscle SOD2 mRNA level at 0.5 h (P<0.05). After once-only eccentric exercise (OE), SOD1, SOD2, and SOD3 mRNA expression significantly increased at 96 h, whereas MDA concentrations decreased at 96 h. After CE, the correlation coefficients of SOD1, SOD2, SOD3 mRNA expression levels and MDA concentrations were -0.814, -0.763, -0.845 (all P<0.05) at 12 h.


CONCLUSIONS
Regular eccentric exercise, especially CE could enhance SOD1 and SOD2 mRNA expression in acute stage and the SOD2 mRNA expression correlates to MDA concentration in vivo, which may improve the oxidative adaption ability of skeletal muscles.
Department of Radiology, Shengjing Hospital of China Medical University, Shenyang, China.
Heng
H
Zhao
Jiani
J
Liu
Shinong
S
Pan
Yingwei
Y
Sun
Qi
Q
Li
Fei
F
Li
Li
L
Ma
Qiyong
Q
Guo
D000222:Adaptation, Physiological; D000818:Animals; D015870:Gene Expression; D008297:Male; D008315:Malondialdehyde / Q000378:metabolism*; D010805:Physical Conditioning, Animal / Q000379:methods; D052097:Quadriceps Muscle / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013482:Superoxide Dismutase / Q000235:genetics / Q000378:metabolism*; D000072105:Superoxide Dismutase-1; D013997:Time Factors; D000099156:Superoxide Dismutase 2
D008315:Malondialdehyde; D012333:RNA, Messenger; D013482:Superoxide Dismutase; D000072105:Superoxide Dismutase-1; D000099156:Superoxide Dismutase 2; C000606292:Sod1 protein, rat; C499089:Sod3 protein, rat