Premium
Hypothalamic dopaminergic activity improves aerobic performance in rats.
Author(s) -
Balthazar Cláudio Heitor,
Coimbra Cândido Celso
Publication year - 2008
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.22.1_supplement.1176.9
Subject(s) - saline , eticlopride , endocrinology , dopaminergic , medicine , antagonist , ketamine , chemistry , dopamine , treadmill , anesthesia , sch 23390 , receptor
Male Wistar rats (250–300g) were used in all experiments. Under anesthesia with an association of ketamine and xylazine, the animals received an implant of guide cannulae into the right lateral cerebral ventricle. After recovery from surgery, the rats were familiarized to run on a motor‐driven treadmill during 5 consecutive days. On the day of the experiments, 2μl of dopamine (Dp) 5x10 −3 M or SCH23390 5x10 −3 M (D1 antagonist) or Eticlopride 5x10 −3 M (D2 antagonist) or saline, at random, was intracerebroventricularly (ICV) injected and then the rats were submitted to a progressive exercise protocol on a treadmill until fatigue. The ICV injection of Dp 5x10 −3 M improved AP in rats, as seen by increased time to fatigue: Saline: 16.8±3.0 min vs Dp: 26.3±5.0 min (p<0.03; n=6) and increased VO 2 max. ΔVO 2 max: Saline: 18.2±2.2 ml.Kg.min −1 vs Dp: 26.5±5.5 ml.Kg.min −1 (p<0.03; n=6). In contrast, the ICV injection of D1 and D2 antagonists reduced the time to fatigue in rats about 75% and 50% respectively (p<0.03 vs Saline; n=6) and reduced VO 2 max. ΔVO 2 max: SCH23390: 4.4±2.2 ml.Kg.min −1 ; Eticlopride: 11.4±1.2 ml.Kg.min −1 (p<0.03 vs Saline: 18.2±2.2 ml.Kg.min −1 ; n=6).We conclude that central dopaminergic tonus has an ergogenic influence on running performance and VO 2 max. Supported by: CNPq; FAPEMIG.