Exercise intensity, inflammatory signaling, and insulin resistance in obese rats.
OBJECTIVE
To evaluate the effects of intensity of exercise on insulin resistance and the expression of inflammatory proteins in the skeletal muscle of diet-induced obese (DIO) rats after a single bout of exercise.


METHODS
In the first exercise protocol, the rats swam for two 3-h bouts, separated by a 45-min rest period (with 6 h in duration--O + EXE), and in the second protocol, the rats were exercised with 45 min of swimming at 70% of the maximal lactate steady state--SS (DIO + MLSS).


RESULTS
Our data demonstrated that both protocols of exercise increased insulin sensitivity and increased insulin-stimulated tyrosine phosphorylation of insulin receptor and insulin receptor substrate 1 and serine phosphorylation of protein kinase B in the muscle of DIO rats by the same magnitude. In parallel, both exercise protocols also reduced protein tyrosine phosphatase 1B activity and insulin receptor substrate 1 serine phosphorylation, with concomitant reduction in c-jun N-terminal kinase and IJB kinase activities in the muscle of DIO rats in a similar fashion.


CONCLUSIONS
Thus, our data demonstrate that either exercise protocols with low intensity and high volume or exercise with moderate intensity and low volume represents different strategies to restore insulin sensitivity with the same efficacy.
Da Silva
Adelino S R
AS
Department of Internal Medicine, Faculty of Medical Sciences State University of Campinas-UNICAMP, Campinas, São Paulo, Brazil.
Pauli
José R
JR
Ropelle
Eduardo R
ER
Oliveira
Alexandre G
AG
Cintra
Dennys E
DE
De Souza
Claudio T
CT
Velloso
Lício A
LA
Carvalheira
José B C
JB
Saad
Mario J A
MJ
D000818:Animals; D007249:Inflammation / Q000276:immunology*; D007333:Insulin Resistance / Q000276:immunology*; D018482:Muscle, Skeletal / Q000378:metabolism; D009765:Obesity; D010805:Physical Conditioning, Animal / Q000502:physiology*; D005082:Physical Exertion / Q000502:physiology*; D051381:Rats; D013550:Swimming / Q000502:physiology