Tags

Type your tag names separated by a space and hit enter

Responses of plasma glutamine, free tryptophan and branched-chain amino acids to prolonged exercise after a regime designed to reduce muscle glycogen.

Abstract

Prolonged exercise can elicit a reduction in the plasma glutamine concentration and an increase in the plasma concentration ratio of free tryptophan (FTrp) to branched-chain amino acids (BCAA). The purpose of this investigation was to study the effects of a 60-min bout of vigorous treadmill running with dietary manipulation on plasma concentrations of glutamine, FTrp and BCAA after an exercise and diet regime designed to reduce muscle glycogen. Seven male distance runners [mean (SD) age: 29.3 (2.1) years; VO2max: 62.7 (3.3) ml.kg-1.min-1] acted as subjects. Each undertook a regime designed to reduce muscle glycogen, then performed a 60-min treadmill run (75% VO2max) under two dietary conditions: after a 14-h fast (fasted) and after ingestion of a high carbohydrate meal (30 kJ.kg-1: 80% carbohydrate, 10% protein, 10% fat) 3 h before running (fed). Plasma concentrations of glutamine, FTrp, BCAA, free fatty acids (FFA), glycerol and glucose were measured 5 min before and 5 min after the run, under each dietary condition. Plasma glutamine did not change in response to exercise when fasted (P > 0.05), but increased when fed (P = 0.007). Plasma FTrp increased under both dietary conditions (P < 0.001), but the magnitude of this increase was greater when fasted than when fed (P < 0.001). Plasma BCAA did not change under either dietary condition (P < 0.05). Increases in the plasma FTrp/BCAA ratio reflected increases in plasma FFA and glycerol concentrations (P < 0.001; both dietary conditions) and these changes were all greater under fasted conditions when a fall in blood glucose concentration was observed (P = 0.007). These data emphasise the importance of dietary carbohydrate intake between repeated bouts of prolonged exercise on responses of plasma glutamine, FTrp and BCAA during subsequent exercise.

Authors+Show Affiliations

,

Department of Physical Education, De Montfort University, Bedford, UK.

, ,

Source

MeSH

Adult
Amino Acids, Branched-Chain
Dietary Carbohydrates
Exercise
Exercise Test
Fasting
Glutamine
Glycogen
Humans
Male
Muscle, Skeletal
Tryptophan

Pub Type(s)

Journal Article

Language

eng

PubMed ID

9202952

Citation

Zanker, C L., et al. "Responses of Plasma Glutamine, Free Tryptophan and Branched-chain Amino Acids to Prolonged Exercise After a Regime Designed to Reduce Muscle Glycogen." European Journal of Applied Physiology and Occupational Physiology, vol. 75, no. 6, 1997, pp. 543-8.
Zanker CL, Swaine IL, Castell LM, et al. Responses of plasma glutamine, free tryptophan and branched-chain amino acids to prolonged exercise after a regime designed to reduce muscle glycogen. Eur J Appl Physiol Occup Physiol. 1997;75(6):543-8.
Zanker, C. L., Swaine, I. L., Castell, L. M., & Newsholme, E. A. (1997). Responses of plasma glutamine, free tryptophan and branched-chain amino acids to prolonged exercise after a regime designed to reduce muscle glycogen. European Journal of Applied Physiology and Occupational Physiology, 75(6), pp. 543-8.
Zanker CL, et al. Responses of Plasma Glutamine, Free Tryptophan and Branched-chain Amino Acids to Prolonged Exercise After a Regime Designed to Reduce Muscle Glycogen. Eur J Appl Physiol Occup Physiol. 1997;75(6):543-8. PubMed PMID: 9202952.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Responses of plasma glutamine, free tryptophan and branched-chain amino acids to prolonged exercise after a regime designed to reduce muscle glycogen. AU - Zanker,C L, AU - Swaine,I L, AU - Castell,L M, AU - Newsholme,E A, PY - 1997/1/1/pubmed PY - 1997/1/1/medline PY - 1997/1/1/entrez SP - 543 EP - 8 JF - European journal of applied physiology and occupational physiology JO - Eur J Appl Physiol Occup Physiol VL - 75 IS - 6 N2 - Prolonged exercise can elicit a reduction in the plasma glutamine concentration and an increase in the plasma concentration ratio of free tryptophan (FTrp) to branched-chain amino acids (BCAA). The purpose of this investigation was to study the effects of a 60-min bout of vigorous treadmill running with dietary manipulation on plasma concentrations of glutamine, FTrp and BCAA after an exercise and diet regime designed to reduce muscle glycogen. Seven male distance runners [mean (SD) age: 29.3 (2.1) years; VO2max: 62.7 (3.3) ml.kg-1.min-1] acted as subjects. Each undertook a regime designed to reduce muscle glycogen, then performed a 60-min treadmill run (75% VO2max) under two dietary conditions: after a 14-h fast (fasted) and after ingestion of a high carbohydrate meal (30 kJ.kg-1: 80% carbohydrate, 10% protein, 10% fat) 3 h before running (fed). Plasma concentrations of glutamine, FTrp, BCAA, free fatty acids (FFA), glycerol and glucose were measured 5 min before and 5 min after the run, under each dietary condition. Plasma glutamine did not change in response to exercise when fasted (P > 0.05), but increased when fed (P = 0.007). Plasma FTrp increased under both dietary conditions (P < 0.001), but the magnitude of this increase was greater when fasted than when fed (P < 0.001). Plasma BCAA did not change under either dietary condition (P < 0.05). Increases in the plasma FTrp/BCAA ratio reflected increases in plasma FFA and glycerol concentrations (P < 0.001; both dietary conditions) and these changes were all greater under fasted conditions when a fall in blood glucose concentration was observed (P = 0.007). These data emphasise the importance of dietary carbohydrate intake between repeated bouts of prolonged exercise on responses of plasma glutamine, FTrp and BCAA during subsequent exercise. SN - 0301-5548 UR - https://www.unboundmedicine.com/medline/citation/9202952/Responses_of_plasma_glutamine_free_tryptophan_and_branched_chain_amino_acids_to_prolonged_exercise_after_a_regime_designed_to_reduce_muscle_glycogen_ L2 - https://medlineplus.gov/exerciseandphysicalfitness.html DB - PRIME DP - Unbound Medicine ER -