Abstract
We have measured concentrations of 26 serum amino acids in 46 subjects (aged 17-75 years), with the following neurological diseases: amyotrophic lateral sclerosis, n=7; peripheral neuropathy, n=5; muscular dystrophy, n=7; mitochondriopathy, n=3; metabolic myopathy (others), n=2; inflammatory myopathy, n=4; mononeuropathy, n=3; controls (patients with symptoms suggesting neuromuscular system dysfunction without objective evidence of neuromuscular disease), n=15, before and after prolonged muscular effort. Tests were done on a bicycle ergometer at the individual aerobic/anaerobic threshold determined for each subject in preliminary tests. Using a stepwise multiple linear regression model, age emerged as a significant negative predictor (P<0.05) of the post/before ratio of the levels of five amino acids. We conclude that an increase in recovery time and a reduction in training capacity with aging could be linked to these changes. The cause is assumed to be principally a reduction in glycogen storage in muscle with increasing age; this situation could possibly be improved by consumption of carbohydrate before or during exercise, or also during rehabilitation exercise or training in neuromuscular or other diseases.
References
Apr 12, 1979·European Journal of Applied Physiology and Occupational Physiology·J DécombazJ R Poortmans
May 1, 1991·Canadian Journal of Physiology and Pharmacology·K K McCullyB Chance
Jan 1, 1991·European Journal of Applied Physiology and Occupational Physiology·E BlomstrandE A Newsholme
Mar 1, 1987·Archives internationales de physiologie et de biochimie·P K MohanK Indira
May 1, 1988·Acta Physiologica Scandinavica·E BlomstrandE A Newsholme
Apr 1, 1974·Scandinavian Journal of Clinical and Laboratory Investigation·R C HarrisL O Nordesjö
Jan 1, 1984·European Journal of Applied Physiology and Occupational Physiology·C Bastien, J Sánchez
Jul 1, 1984·Journal of Gerontology·M G PluskalV R Young
Jun 1, 1984·Mechanisms of Ageing and Development·C A Blazejowski, G C Webster
Nov 1, 1993·Journal of Applied Physiology·A R CogganP M Robitaille
Jan 1, 1997·European Journal of Applied Physiology and Occupational Physiology·C L ZankerE A Newsholme