Effects of ovariectomy and resistance training on MMP-2 activity in skeletal muscle.
Matrix metallopeptidases (MMPs) are crucial to the maintenance of healthy tissue. The aim of this study was to investigate MMP-2 activity in gastrocnemius, soleus, tibialis anterior (TA), and extensor digitorium longus (EDL) muscle after resistance training in ovariectomized rats. Wistar adult female rats were grouped into 7 groups (n = 10 per group): sedentary (Sed-Intact); ovariectomized sedentary (Sed-Ovx); pseudo-ovariectomized sedentary (Sed-Pseudo); acute exercise (AcuteEx-Intact); ovariectomized acute exercise (AcuteEx-Ovx); strength trained (ChronicEx-Intact); and ovariectomized strength trained (ChronicEx-Ovx). A 12-week resistance training period, during which the animals climbed a 1.1-m vertical ladder with weights secured to their tails, was used. The sessions were performed once every 3 days, with 4-9 climbs and 8-12 dynamic movements per climb. The MMP-2 activity was analyzed by zymography. There was higher MMP-2 activity in soleus muscle in the ChronicEx-Intact and ChronicEx-Ovx groups, and lower MMP-2 activity in the AcuteEx-Ovx group, compared with the Sed-Intact group (p < or =0.05). The Sed-Ovx and ChronicEx-Ovx groups presented lower MMP-2 activity than the Sed-Intact group in TA. There was higher MMP-2 activity in AcuteEx-Intact and the AcuteEx-Ovx compared with the Sed-Intact and Sed-Ovx in TA, respectively (p < or = 0.05). In TA and EDL, training increased MMP-2 activity in the Sed-Intact group. No statistically significant alterations were observed for gastrocnemius muscle. Strength training increases MMP-2 activity in soleus, TA, and EDL muscle, which may be important for muscle remodeling. Ovariectomy downregulates MMP-2 in TA and EDL, which may compromise muscle function.
Prestes
Jonato
J
Department of Physiological Sciences, Federal University of Sao Carlos, Sao Carlos, Brazil. jonatop@gmail.com
de Cássia Marqueti
Rita
R
Shiguemoto
Gilberto Eiji
GE
Leite
Richard Diego
RD
Pereira
Guilherme Borges
GB
Selistre-de-Araújo
Heloisa Sobreiro
HS
Baldissera
Vilmar
V
de Andrade Perez
Sérgio Eduardo
SE
D000818:Animals; D005260:Female; D020778:Matrix Metalloproteinase 2 / Q000378:metabolism*; D009119:Muscle Contraction; D053580:Muscle Strength; D018482:Muscle, Skeletal / Q000201:enzymology*; D010052:Ovariectomy; D051381:Rats; D017208:Rats, Wistar; D055070:Resistance Training; D013997:Time Factors
D020778:Matrix Metalloproteinase 2; C522363:Mmp2 protein, rat