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Influence of physical exercise on skeletal muscle trophism and myostatin signaling in rats subjected to intermittent feeding
Author(s) -
Martinez Paula F,
Oliveira Ana Priscila C,
Gois Priscilla B,
Gomes Mariana J,
Pagan Luana U,
Morais Camila S,
Muzili Nayara A,
Ota Gabriel E,
Carvalho Marianna R,
Souza Albert S,
Okoshi Katashi U,
Okoshi Marina P,
OliveiraJunior Silvio A
Publication year - 2017
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.31.1_supplement.1019.7
Subject(s) - myostatin , medicine , endocrinology , follistatin , skeletal muscle , soleus muscle , gastrocnemius muscle , analysis of variance , caloric theory , sed
Background Intermittent feeding (IF) is often used as an alternative to caloric restriction and characterized by alternating cycles of ad libitum feeding and fasting. The main consequence of caloric restriction on skeletal muscle is fiber size reduction, which pathophysiological mechanism is not well known. This study aimed to evaluate the influence of exercise on skeletal muscle morphology and myostatin signaling in rats subjected to intermittent feeding. Methods Male Wistar rats (n=40) were allocated into four groups: sedentary control (C‐S), control + physical exercise (C‐Ex), sedentary intermittent feeding (IF‐S), and intermittent feeding + physical exercise (IF‐Ex). The C‐S and C‐Ex groups were fed ad libitum , and IF‐S and IF‐Ex groups had ad libitum access to food on alternating days. Rats from C‐Ex and IF‐Ex underwent into a treadmill‐exercise protocol for 90 days. Functional capacity was assessed by maximal exercise test on treadmill. Myostatin and follistatin protein expression was evaluated by Western blot in soleus and gastrocnemius (white portion) muscles. Statistics: two‐way ANOVA and Tukey. Results Functional capacity was improved in exercised groups compared to respective controls. Exercise, as an independent factor, reduced myostatin expression in gastrocnemius muscle (C‐S 1.0±0.3; IF‐S 0.9±0.3; C‐Ex 0.8±0.1; IF‐Ex 0.8±0.1). There was no difference between groups for myostatin expression in soleus muscle, and follistatin expression in both gastrocnemius and soleus muscle. Other results are shown in Table. Conclusion Intermittent feeding promotes a physical exercise‐reversible atrophy in soleus muscle, but not in white gastrocnemius muscle of rats. Although myostatin may be modulated by physical exercise, it does not seem to participate on intermittent feeding‐induced muscle atrophy. Support or Funding Information Financial support: CAPESVariables C‐S IF‐S C‐Ex IF‐ExGastrocnemius mass (g) 2.36±0.28 1.92±0.27 * 2.35±0.17 2.12±0.13 # †Soleus mass (g) 0.18±0.03 0.14±02 * 0.17±0.02 0.16±0.02Gastrocnemius CSA (μm 2 ) 3878±308 3156±434 * 3667±270 3101±398 †Soleus CSA (μm 2 ) 3982±543 3177±314 * 3649±354 3617±160 #CSA: fiber cross‐sectional area. Mean ± standard deviation. Two‐way ANOVA and Tukey; * p <0.05 vs . C‐S; # p <0.05 vs . IF‐S; † p <0.05 vs . C‐Ex.