Administration of a GABAB agonist baclofen before running to exhaustion in the rat: effects on performance and on some indicators of fatigue.
The present study was designed to examine the effects of administration of a GABAergic agonist (Baclofen) on run-time to exhaustion in trained and untrained rats, and on some indicators of fatigue. Run-time to exhaustion on a treadmill set at a speed of 25 m.min-1 was significantly increased in both untrained (p < 0.01) and trained rats (p < 0.005) administered with baclofen one hour before the exercise. The animals who had run the longest time displayed the lowest concentrations of liver and muscle glycogen, and a decrease in plasma glucose concentrations (p < 0.05). The results of this investigation suggest that fatigue during prolonged exercise can be influenced by pharmacological administration of a GABAergic agonist. Indicators of fatigue such as glycemia, liver and muscular glycogen are not the limiting factors of performance and central mechanisms play a key role at exhaustion.
Abdelmalki
A
A
Institut de Médecine Aérospatiale du Service de Santé des Armées, Brétigny sur Orge, France.
Merino
D
D
Bonneau
D
D
Bigard
A X
AX
Guezennec
C Y
CY
D000704:Analysis of Variance; D000818:Animals; D001418:Baclofen / Q000494:pharmacology*; D001786:Blood Glucose / Q000032:analysis; D005221:Fatigue / Q000503:physiopathology*; D018755:GABA Agonists / Q000494:pharmacology*; D006003:Glycogen / Q000032:analysis; D008099:Liver / Q000187:drug effects / Q000378:metabolism; D008297:Male; D009043:Motor Activity / Q000187:drug effects*; D018482:Muscle, Skeletal / Q000187:drug effects / Q000378:metabolism; D010805:Physical Conditioning, Animal; D010807:Physical Endurance / Q000187:drug effects*; D010919:Placebos; D051381:Rats; D017208:Rats, Wistar; D012420:Running / Q000502:physiology*; D013997:Time Factors
D001786:Blood Glucose; D018755:GABA Agonists; D010919:Placebos; D006003:Glycogen; D001418:Baclofen