Sulfur Amino Acid Restriction Enhances Exercise Capacity in Mice by Boosting Fat Oxidation in Muscle.

Dietary restriction of the sulfur-containing amino acids methionine and cysteine (SAAR) improves body composition, enhances insulin sensitivity, and extends lifespan; benefits seen also with endurance exercise. Yet, the impact of SAAR on skeletal muscle remains largely unexplored. Here we demonstrate that one week of SAAR in sedentary, young, male mice increases endurance exercise capacity.

Glycine homeostasis requires reverse SHMT flux.

The folate-dependent enzyme serine hydroxymethyltransferase (SHMT) reversibly converts serine into glycine and a tetrahydrofolate-bound one-carbon unit. Such one-carbon unit production plays a critical role in development, the immune system, and cancer. Using rodent models, here we show that the whole-body SHMT flux acts to net consume rather than produce glycine.

Glycine homeostasis requires reverse SHMT flux.

The folate-dependent enzyme serine hydroxymethyltransferase (SHMT) reversibly converts serine into glycine and a tetrahydrofolate-bound one-carbon unit. Such one-carbon unit production plays a critical role in development, the immune system, and cancer. Here we show that the whole-body SHMT flux acts to net consume rather than produce glycine.

Initial signaling response to acute exercise bout is similar in hearts of rats bred for divergent exercise capacities.

Rats artificially selected as low capacity runners (LCR) exhibit features of the metabolic syndrome, and blunted exercise training-induced cardiac hypertrophy compared with high capacity runners (HCR). We tested the hypothesis that the divergent cardiac phenotypes may be due to diminished activation of signaling proteins in LCR vs HCR rats. LCR (n=18) and HCR (n=18) rats were randomly assigned to acute exercise or control groups.