Acute Response of PGC-1α and IGF-1 Isoforms to Maximal Eccentric Exercise in Skeletal Muscle of Postmenopausal Women. Issue 4 (April 2016)

• Record Type: Journal Article
• Authors: Dieli-Conwright, Christina M.; Kiwata, Jacqueline L.; Tuzon, Creighton T.; Spektor, Tanya M.; Sattler, Fred R.; Rice, Judd C.; Schroeder, Edward Todd
• Is Part Of: Journal of strength and conditioning research. Volume 30:Issue 4(2016)
• Publication Date: 2016-04
• Subjects: PGC-1α4 -- MGF -- myostatin -- resistance exercise -- sarcopenia; Physical education and training -- Periodicals; Weight training -- Physiological aspects -- Periodicals; Physical fitness -- Periodicals; 613.7
• DOI: 10.1519/JSC.0000000000001171
• Languages: English
• ISSNs: 1064-8011

Abstract

Abstract : Abstract: Dieli-Conwright, CM, Kiwata, JL, Tuzon, C, Spektor, TM, Sattler, FR, Rice, JC, and Schroeder, ET. Acute response of PGC-1α and IGF-1 isoforms to maximal eccentric exercise in skeletal muscle of postmenopausal women. J Strength Cond Res 30(4): 1161–1170, 2016—PGC-1α4, a novel isoform of the transcriptional coactivator PGC-1α, was recently postulated to modulate the expression of anabolic and catabolic genes and therefore regulate skeletal muscle hypertrophy. Resting levels of PGC-1α4 messenger RNA (mRNA) expression were found to increase in healthy adults after resistance training. However, the acute effect of resistance exercise (RE) on PGC-1α4 expression in populations prone to progressive muscle loss, such as postmenopausal women, has not been evaluated. Here, we investigated alterations in mRNA expression of PGC-1α4 and PGC-1α1, a regulator of muscle oxidative changes, in postmenopausal women after high-intensity eccentric RE and analyzed these findings with respect to changes in insulin-like growth factor (IGF)-1 and catabolic gene expression. Nine postmenopausal women (age, 57.9 ± 3.2 years) performed 10 sets of 10 maximal eccentric repetitions of single-leg extension with 20-second rest periods between sets. Muscle biopsies were obtained from the vastus lateralis of the exercised leg before and 4 hours after the RE bout with mRNA expression determined by quantitative real-time polymerase chain reaction. No significant changes in the mRNA expression of either PGC-1α isoform were observed after acute eccentric RE ( p > 0.05). IGF-1Ea mRNA expression significantly increased ( p ⩽ 0.05), whereas IGF-1Eb and mechano-growth factor (MGF) did not significantly change ( p > 0.05). PGC-1α4 mRNA expression was associated with reduced mRNA expression of the catabolic gene myostatin ( R = −0.88, p < 0.01), whereas MGF mRNA expression was associated with reduced mRNA expression of the catabolic gene FOXO3A ( R = −0.81, p ⩽ 0.05). These data demonstrate an attenuated response of PGC-1α isoforms to an acute bout of maximal eccentric exercise with short rest periods in postmenopausal women.