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Resistance training increases and protein intake does not influence skeletal muscle aPKC zeta/lambda content in older men and women
Author(s) -
Iglay Heidi B,
Thyfault John P,
Apolzan John W,
Campbell Wayne W
Publication year - 2006
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.20.4.a169
Subject(s) - resistance training , lambda , skeletal muscle , zeta potential , endocrinology , psychology , gerontology , medicine , food science , biology , physics , materials science , nanotechnology , nanoparticle , optics
To assess the effect of resistance training (RT) and protein intake on skeletal muscle insulin signaling protein contents in older people, 14 men and 15 women (BMI 26 ± 1 kg/m 2 ; 61 ± 1 yr; mean ± SEM) completed a 12‐week dietary and RT intervention. They consumed either 0.9 (LP) or 1.2 g protein·kg −1 ·d −1 (HP) and completed RT 3x/wk. With RT, body weight remained stable, fat‐free mass increased and fat mass decreased independent of diet and gender (change from baseline: 2.03 ± 0.51 kg, −1.20 ± 0.45 kg, respectively P < 0.05). Glucose tolerance, assessed with a 75g oral glucose tolerance test, improved with RT. Glucose area under the curve decreased independent of diet and gender (−26%: 3833 ± 330 to 2840 ± 290 mg·dL −1 ·2hr −1 , P < 0.05). Insulin and C‐peptide responses differed between diets; both decreased in LP + RT (−21%: 4987 ± 587 to 3956 ± 513 mu·L −1 ·2hr −1 ; −14%: 179120 ± 20782 to 154648 ± 17023 pmol·L −1 ·2hr −1 , P < 0.05) and were unchanged in HP + RT. Vastus lateralis insulin receptor, insulin receptor substrate‐1 and Akt contents were unchanged. Atypical protein kinase‐C (aPKC) zeta/lambda content increased 56% with RT independent of diet and gender (P < 0.05). The increase in aPKC zeta/lambda was not correlated with changes in body composition or whole body glucose metabolism (P > 0.05). These results indicate that resistance training alters a portion of the skeletal muscle insulin signaling pathway in older people, and protein intake does not influence this change. Support: Am Egg Board – Egg Nutr Ctr