Interesting read for you guys as to the effects of amino acids on protein synthesis in people with minimal blood flow to the legs (claudication). And this is without exercise treatment, just amino acid (from a shake) enduced protein synthesis. Coupled with resistance training...?
"Amino acids stimulate leg muscle protein synthesis in peripheral arterial
disease.
Killewich LA, Tuvdendorj D, Bahadorani J, Hunter GC, Wolfe RR.
Department of Surgery, The University of Texas Medical Branch, Galveston, TX
77555, USA.
lakillew@utmb.edu
OBJECTIVE: Older patients with peripheral arterial disease (PAD) and
intermittent claudication have impaired walking ability resulting from reduced
lower extremity blood flow. Evidence suggests that leg muscle abnormalities may
also contribute to walking intolerance in claudicants. In healthy elderly
people, leg muscle protein synthesis can be augmented by nutritional
supplementation with amino acids; preliminary data suggest that this increases
muscle mass, walking ability, and functional status. In this study, we
investigated whether amino acid supplementation would improve leg muscle protein
synthesis in elderly PAD subjects, given that reduced leg blood flow might
restrict the availability of amino acids to muscle. METHODS: Two groups
participated in the study: a group of 11 claudicants (mean age, 62 years; mean
ankle-brachial index, 0.62; 46% male) and a group of 9 age- and sex-matched
healthy controls (mean ankle-brachial index, 1.1). Both groups underwent
measurement of leg blood flow by using strain gauge plethysmography, as well as
measurement of baseline and amino acid-stimulated protein synthesis in leg
muscle. Protein synthesis was quantified from calf muscle biopsy samples by
measurement of the fractional synthetic rate (FSR) of protein, by using the
incorporation of the stable isotope l-[ring-(2)H(5)]-phenylalanine into muscle
protein. Total protein was extracted from muscle samples, and gas
chromatography/mass spectroscopy methodology was used to measure incorporation
rates. After measurement of basal FSR, all subjects were given an oral drink of
15 g of essential amino acids, and the measurements of FSR were repeated. Data
are expressed as mean +/- SD; statistical analysis of differences between the
two groups (with and without amino acid supplementation) was performed by using
analysis of variance with repeated measures. RESULTS: Calf blood flow was
reduced in the PAD subjects compared with controls (1.44 +/- 0.53 mL/min per 100
mg of tissue vs 2.40 +/- 0.57 mL/min per 100 mg of tissue; P = .005; t test).
FSR in the basal state was equivalent between the two groups (healthy, 0.060%
+/- 0.025% per hour; PAD, 0.061% +/- 0.029% per hour; P = .97). Equivalent
increases (P < .05) occurred in both groups in response to oral amino acid
supplementation (healthy, 0.087% +/- 0.012% per hour; PAD, 0.104% +/- 0.041% per
hour; P > .05; analysis of variance). CONCLUSIONS:
Despite reduced leg blood
flow, elderly PAD patients synthesize calf muscle protein in the basal state in
a fashion similar to that in healthy elderly people. More importantly,
administration of exogenous amino acids produces a significant increase in
protein synthesis in these patients that is also equivalent to that in healthy
elderly people. Our goal is to use these results as the basis for an
intervention study to determine whether long-term oral amino acids, by
augmenting calf muscle protein synthesis, increase calf muscle mass, walking
ability, and functional status in elderly claudicants."