Pre-exercise branched-chain amino acid administration increases endurance performance in rats.
This study investigated the effects of pre-exercise branched-chain amino acid (BCAA) administration on blood ammonia levels and on time to exhaustion during treadmill exercise in rats. Adult female Wistar rats were trained on a motor driven treadmill. After a 24-h fast, rats were injected intraperitoneally (i.p.) with 1 mL of placebo or BCAA (30 mg), 5 min before performing 30 min of submaximal exercise (N = 18) or running to exhaustion (N = 12). In both cases, rats were sacrificed immediately following exercise, and blood was collected for the measurement of glucose, nonesterified fatty acid (NEFA), lactic acid, BCAA, ammonia, and free-tryptophan (free-TRP) levels. Control values were obtained from sedentary rats that were subjected to identical treatments and procedures (N = 30). Plasma BCAA levels increased threefold within 5 min after BCAA administration. Mean run time to exhaustion was significantly longer (P < 0.01) after BCAA administration (99 +/- 9 min) compared with placebo (76 +/- 4 min). During exercise, blood ammonia levels were significantly higher (P < 0.01) in the BCAA treated compared with those in the placebo treated rats both in the 30-min exercise bout (113 +/- 25 mumol.L-1 (BCAA) vs 89 +/- 16 mumol.L-1) and following exercise to exhaustion (186 +/- 44 mumol.L-1 (BCAA) vs 123 +/- 19 mumol.L-1). These data demonstrate that BCAA administration in rats results in enhanced endurance performance and an increase in blood ammonia during exercise.
Calders
P
P
Laboratory of Normal and Pathological Physiology, University of Gent, Belgium.
Pannier
J L
JL
Matthys
D M
DM
Lacroix
E M
EM
D000597:Amino Acids, Branched-Chain / Q000008:administration & dosage*; D000641:Ammonia / Q000097:blood; D000818:Animals; D017079:Exercise Tolerance / Q000502:physiology*; D005260:Female; D010805:Physical Conditioning, Animal / Q000502:physiology; D010807:Physical Endurance / Q000187:drug effects* / Q000502:physiology; D051381:Rats; D017208:Rats, Wistar / Q000502:physiology
D000597:Amino Acids, Branched-Chain; D000641:Ammonia