Serotonergic agonists and antagonists affect endurance performance in the rat.
The purpose of this experiment was to examine the effects of administration of serotonergic (5-HT) agonist and antagonist drugs on run-time to exhaustion (RUN-EXH) in male and female rats. RUN-EXH was reduced (p < 0.05) in a dose related manner by increasing dosages of quipazine dimaleate (QD: general 5-HT agonist) (0-5 mg.kg-1 i.p.) administered immediately prior to exercise (treadmill running at 20 m.min-1 and 5% grade). Conversely, RUN-EXH was increased (p < 0.05) by the greatest dosage of LY 53,857 (LY: 5-HT1C and 5-HT2 antagonist) (1.5 mg.kg-1 i.p.). Drug effects were similar in male and female rats. The negative effects of QD administration on RUN-EXH were not attenuated by administration of the peripherally restricted antagonist, xylamidine tosylate (up to 200 ug.kg-1 i.p.). The results of this investigation indicated that fatigue during prolonged exercise can be influenced by direct pharmacological administration of a serotonergic agonist and antagonist and that the mechanisms underlying these effects are likely to be central (brain) in nature.
Bailey
S P
SP
Department of Exercise Science, School of Public Health, University of South Carolina.
Davis
J M
JM
Ahlborn
E N
EN
D000578:Amidines / Q000008:administration & dosage / Q000494:pharmacology*; D000818:Animals; D004305:Dose-Response Relationship, Drug; D004873:Ergolines / Q000008:administration & dosage / Q000494:pharmacology*; D005260:Female; D007274:Injections, Intraperitoneal; D008297:Male; D010807:Physical Endurance / Q000187:drug effects*; D010919:Placebos; D011814:Quipazine / Q000008:administration & dosage / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar; D012420:Running / Q000502:physiology; D012702:Serotonin Antagonists / Q000008:administration & dosage / Q000494:pharmacology*; D013997:Time Factors
D000578:Amidines; D004873:Ergolines; D010919:Placebos; D012702:Serotonin Antagonists; D011814:Quipazine; C032663:LY 53857; C005894:xylamidine