Post by John A. Casler on Feb 8, 2009 21:12:57 GMT -8
Skeletal Muscle Hypertrophy Following Resistance Training Is Accompanied by a Fiber Type-Specific Increase in Satellite Cell Content in Elderly Men.
Verdijk LB, Gleeson BG, Jonkers RA, Meijer K, Savelberg HH, Dendale P, van Loon LJ.
Department of Human Movement Sciences, Faculty of Health, Medicine and Life Sciences, Maastricht University, P.O. Box 616, 6200 MD Maastricht, the Netherlands. lex.verdijk@bw.unimaas.nl.
We determined muscle fiber type-specific hypertrophy and changes in satellite cell (SC) content following a 12-week resistance training program in 13 healthy, elderly men (72 +/- 2 years). Leg strength and body composition (dual-energy X-ray absorptiometry and computed tomography) were assessed, and muscle biopsy samples were collected. Leg strength increased 25%-30% after training (p < .001). Leg lean mass and quadriceps cross-sectional area increased 6%-9% (p < .001). At baseline, mean fiber area and SC content were smaller in the Type II versus Type I muscle fibers (p < .01). Following training, Type II muscle fiber area increased from 5,438 +/- 319 to 6,982 +/- 503 mum(2) (p < .01). Type II muscle fiber SC content increased from 0.048 +/- 0.003 to 0.084 +/- 0.008 SCs per fiber (p < .001). No changes were observed in the Type I muscle fibers. In older adults, skeletal muscle tissue is still capable of inducing SC proliferation and differentiation, resulting in Type II muscle fiber hypertrophy.
PMID: 19196907 [PubMed - as supplied by publisher]
www.ncbi.nlm.nih.gov/pubmed/19196907?ordinalpos=1&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_DefaultReportPanel.Pubmed_RVDocSum
Verdijk LB, Gleeson BG, Jonkers RA, Meijer K, Savelberg HH, Dendale P, van Loon LJ.
Department of Human Movement Sciences, Faculty of Health, Medicine and Life Sciences, Maastricht University, P.O. Box 616, 6200 MD Maastricht, the Netherlands. lex.verdijk@bw.unimaas.nl.
We determined muscle fiber type-specific hypertrophy and changes in satellite cell (SC) content following a 12-week resistance training program in 13 healthy, elderly men (72 +/- 2 years). Leg strength and body composition (dual-energy X-ray absorptiometry and computed tomography) were assessed, and muscle biopsy samples were collected. Leg strength increased 25%-30% after training (p < .001). Leg lean mass and quadriceps cross-sectional area increased 6%-9% (p < .001). At baseline, mean fiber area and SC content were smaller in the Type II versus Type I muscle fibers (p < .01). Following training, Type II muscle fiber area increased from 5,438 +/- 319 to 6,982 +/- 503 mum(2) (p < .01). Type II muscle fiber SC content increased from 0.048 +/- 0.003 to 0.084 +/- 0.008 SCs per fiber (p < .001). No changes were observed in the Type I muscle fibers. In older adults, skeletal muscle tissue is still capable of inducing SC proliferation and differentiation, resulting in Type II muscle fiber hypertrophy.
PMID: 19196907 [PubMed - as supplied by publisher]
www.ncbi.nlm.nih.gov/pubmed/19196907?ordinalpos=1&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_DefaultReportPanel.Pubmed_RVDocSum