Reduction in plasma leucine after sprint exercise is greater in males than in females

Abstract

There is a pronounced gender difference in the accumulation of plasma ammonia after sprint exercise. Ammonia is a key intermediate in amino acid metabolism, which implies that gender-related differences in plasma and muscle amino acid concentrations after sprint exercise exist. To study this, three bouts of 30-s sprint exercise were performed by healthy females (n=8) and males (n=6). Blood leucine and muscle leucine were collected over the exercise period. Basal arterial plasma and skeletal muscle leucine were 40% higher in males than females (P<0.010 and P<0.020). Plasma, but not muscle, leucine decreased by sprint exercise and more so in males than females (g × t: P=0.025). Increase in ammonia was higher in males than females in both plasma and muscle (g × t: P<0.001 and P=0.003). An opposite pattern was shown for plasma glutamine, where an increase was found in females (P<0.001), but not in males. In conclusion, the lower plasma ammonia after sprint exercise in females seems to be explained by a lower accumulation of ammonia in skeletal muscle and by a buffering of ammonia in the form of glutamine in females. The greater reduction in plasma leucine in males seems to be related to their greater increase in muscle ammonia after sprint exercise.

Nutrient ingestion increased mTOR signaling, but not hVps34 activity in human skeletal muscle after sprint exercise

“…The finding in this study of a decrease in plasma EAA – during repeated bouts of 30‐sec sprint exercise (Esbjornsson et al. ) in fasting condition, support the need for nutrient supply after sprint exercise to maintain or increase muscle mass.…”

Sprint exercise enhances skeletal muscle p70S6k phosphorylation and more so in women than in men

“…, Esbjörrnsson et al . ), may favour an anabolic stimulus after sprint exercise and thereby an increase in mTOR signalling. In addition, the faster recovery of muscle ATP after sprint exercise in women than in men (Esbjörnsson‐Liljedahl et al .…”

Does infectious fever relieve autistic behavior by releasing glutamine from skeletal muscles as provisional fuel?

“…The greater reduction in plasma leucine in males seems to be related to their greater increase in muscle ammonia after sprint exercise.'' [157] Norenberg et al concluded that ammonia may cause astrocytes to swell via oxidative stress -effects of reactive oxygen species like free radicals and peroxides [158]. Rossignol and Frye found that physiologic/metabolic studies of autism in recent years focused largely on four concerns: oxidative stress, immune dysregulation/ inflammation, mitochondrial dysfunction, and environmental toxins [159].…”

“…Woeller recommends 500 mg-1000 mg oral glutamine daily (between meals) for ASD children, to improve gut health, muscle tone, and overall metabolism [55]. Exercise stimulates muscles to take up ammonia and synthesize glutamine [19], but also increases ammonia [157]. Although supplemental glutamine can elevate blood/brain ammonia when the liver is impaired, body-builders and athletes ingest large amounts of glutamine daily; great amounts have been safely given in severe catabolic states [85,169,170].…”