Pauli JR, Ropelle ER, Cintra DE, De Souza CT, da Silva ASR, Moraes JC, Prada PO, de Almeida Leme JAC, Luciano E, Velloso LA, Carvalheira JBC, Saad MJA. Acute exercise reverses aged-induced impairments in insulin signaling in rodent skeletal muscle.
Mech Ageing Dev 2010;
131:323-9. [PMID:
20307567 DOI:
10.1016/j.mad.2010.03.004]
[Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2009] [Revised: 03/08/2010] [Accepted: 03/10/2010] [Indexed: 02/07/2023]
Abstract
The insulin resistance associated with aging is improved by exercise, but the molecular mechanisms of this improvement are not fully understood. We investigated whether the improvement in insulin action, associated with acute exercise in old rats is dependent on the modulation of pIRS-1Ser307, JNK, IkBalpha and PTP-1B. Aging rats were subjected to swimming for two 1.5-h long bouts, separated by a 45min rest period. Sixteen hours after the exercise, the rats were killed and proteins from the insulin signaling pathway were analyzed by immunoblotting. Our results show that the reduction in glucose disappearance rate (Kitt), observed in aged rats, was restored at 16h after exercise. Aging led to an increase in Ser307 phosphorylation of IRS-1, and this was reversed by exercise in the skeletal muscle, in parallel with a reduction in pJNK and IkBalpha degradation. Moreover, aging induced an increase in the expression of PTP-1B and attenuated insulin signaling in the muscle of rats, a phenomenon that was reversed by exercise. Interestingly, the decrease in PTP-1B expression in the muscle of exercised old rats was accompanied by an increase in SIRT1 expression. These results provide new insights into the mechanisms by which exercise restores insulin sensitivity during aging.
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